Polarization

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

Abstract: The generation of Bessel beams (BBs) and their characterization in a wide range of the electromagnetic spectrum are well established. The unique properties of BBs, including their non-diffracting and self-healing nature, make them efficient for use in material science and engineering technology. Here, I investigate the polarization components (s-polarization, p-polarization, transverse polarization, and longitudinal polarization) created in scalar BBs owing to their conical wave front. For emphasis, I provide a theoretical analysis to characterize potential experimental artifacts created in the four polarization components. Further, I provide a brief discussion on how to prevent these artifacts in scalar BBs. To my knowledge, for the first time, I can generate vector BBs in s-polarization and p-polarization via the superposition of two orthogonally polarized scalar BBs. This method of generation can provide the four well-known types of vector modes categorized in the V-point phase singularity vector modes. I suggest a suitable experimental configuration for realizing my theoretical results experimentally. The present analysis is very practical and beneficial for young researchers who seek to utilize BBs in light applications of modern science and technology. Keywords: Bessel beam; p-polarization; s-polarization; vector Bessel beam; Fresnel reflection; radial vector beam; azimuthal vector beam; orbital angular momentum

Classification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

In microscopy, the objective lenses are the optical elements closest to the specimen. The objective lens gathers light from the specimen, which is focused to produce the real image that is seen on the ocular lens. Objective lenses are the most complex part of the microscope due to their multi-element design. It is this complexity that makes the objectives the most important components of the device.Objectives lenses greatly vary in design and quality. As such, they can be roughly classified based on:Intended purposeMicroscopy methodPerformanceMagnificationAberration correction In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

 Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Nov 01, 22 04:44 PMDeltaproteobacteria is a large group (Class) of Gram-negative bacteria within the Phylum Proteobacteria. It consists of ecologically and metabolically diverse members. Read more here.Read MoreChemoorganotrophs - Definition, and ExamplesOct 26, 22 05:01 PMChemoorganotrophs also known as organotrophs, include organisms that obtain their energy from organic chemicals like glucose. This process is known as chemoorganotrophy. Read more here.Read MoreBetaproteobacteria – Examples, Characteristics and FunctionOct 25, 22 03:44 PMBetaproteobacteria is a heterogeneous group in the phylum Proteobacteria whose members can be found in a range of habitats from wastewater and hot springs to the Antarctic. Read more here.Read More

Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

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Linearpolarization

Rao, A.S. Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization. Photonics 2023, 10, 1092. https://doi.org/10.3390/photonics10101092

Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

 Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

 Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

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 Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

polarization中文

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Rao, A. Srinivasa. 2023. "Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization" Photonics 10, no. 10: 1092. https://doi.org/10.3390/photonics10101092

**  Be sure to take the utmost precaution and care when performing a microscope experiment.  MicroscopeMaster is not liable for your results or any personal issues resulting from performing the experiment. The MicroscopeMaster website is for educational purposes only.

Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Today, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

The refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Essentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Return to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Rao AS. Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization. Photonics. 2023; 10(10):1092. https://doi.org/10.3390/photonics10101092

Feature papers represent the most advanced research with significant potential for high impact in the field. A Feature Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for future research directions and describes possible research applications.

Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

S-polarization

Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Politicalpolarization

Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Ellipticalpolarization

Objectives lenses greatly vary in design and quality. As such, they can be roughly classified based on:Intended purposeMicroscopy methodPerformanceMagnificationAberration correction In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

The material on this page is not medical advice and is not to be used for diagnosis or treatment. Although care has been taken when preparing this page, its accuracy cannot be guaranteed. Scientific understanding changes over time.**  Be sure to take the utmost precaution and care when performing a microscope experiment.  MicroscopeMaster is not liable for your results or any personal issues resulting from performing the experiment. The MicroscopeMaster website is for educational purposes only.

The overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

In microscopy, the objective lenses are the optical elements closest to the specimen. The objective lens gathers light from the specimen, which is focused to produce the real image that is seen on the ocular lens. Objective lenses are the most complex part of the microscope due to their multi-element design. It is this complexity that makes the objectives the most important components of the device.Objectives lenses greatly vary in design and quality. As such, they can be roughly classified based on:Intended purposeMicroscopy methodPerformanceMagnificationAberration correction In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Return to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Essentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

 Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Oct 26, 22 05:01 PMChemoorganotrophs also known as organotrophs, include organisms that obtain their energy from organic chemicals like glucose. This process is known as chemoorganotrophy. Read more here.Read MoreBetaproteobacteria – Examples, Characteristics and FunctionOct 25, 22 03:44 PMBetaproteobacteria is a heterogeneous group in the phylum Proteobacteria whose members can be found in a range of habitats from wastewater and hot springs to the Antarctic. Read more here.Read More

 In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

 Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Feature papers are submitted upon individual invitation or recommendation by the scientific editors and must receive positive feedback from the reviewers.

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Objectives lenses greatly vary in design and quality. As such, they can be roughly classified based on:Intended purposeMicroscopy methodPerformanceMagnificationAberration correction In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

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For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

The differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Rao, A.S. Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization. Photonics 2023, 10, 1092. https://doi.org/10.3390/photonics10101092

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Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Rao, A. Srinivasa. 2023. "Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization" Photonics 10, no. 10: 1092. https://doi.org/10.3390/photonics10101092

Rao AS. Illustrations of Bessel Beams in s-Polarization, p-Polarization, Transverse Polarization, and Longitudinal Polarization. Photonics. 2023; 10(10):1092. https://doi.org/10.3390/photonics10101092

Circularly polarized light

Read MoreChemoorganotrophs - Definition, and ExamplesOct 26, 22 05:01 PMChemoorganotrophs also known as organotrophs, include organisms that obtain their energy from organic chemicals like glucose. This process is known as chemoorganotrophy. Read more here.Read MoreBetaproteobacteria – Examples, Characteristics and FunctionOct 25, 22 03:44 PMBetaproteobacteria is a heterogeneous group in the phylum Proteobacteria whose members can be found in a range of habitats from wastewater and hot springs to the Antarctic. Read more here.Read More

Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Read MoreBetaproteobacteria – Examples, Characteristics and FunctionOct 25, 22 03:44 PMBetaproteobacteria is a heterogeneous group in the phylum Proteobacteria whose members can be found in a range of habitats from wastewater and hot springs to the Antarctic. Read more here.Read More

Intended purposeMicroscopy methodPerformanceMagnificationAberration correction In general, objective lenses are responsible for:Primary image formationDetermine the quality of the image producedThe total magnificationThe overall resolutionClassification based on Microscopy MethodThe differences in microscopy methods can largely be attributed to the different types of objective lenses used. Objective lenses classified according to microscopy methods include: Reflected dark field objectives - Have a special construction that consists of a 360 degree hollow chamber that surrounds the centrally located lens element.Differential interference contrast (DIC objectives) - Uses stain-free optical elements and relies on the action of Nomarski prisms (or Wollaston prism) which influence optical path differences between sheared light beams at the rear focal plane.Fluorescence objectives - designed with quartz and special glass with high transmission from ultraviolet to the infrared regions.Phase contrast objectives -These types of objectives are divided in to several categories depending on construction and neutral density of internal phase ring. These include; dark low objectives (DL) Dark low low objectives (DLL) Apodized dark low objectives (ADL) Dark medium objectives (DM) Bright medium objectives (BM).Take a look at the different Microscopy Imaging Techniques here.Classification based on MagnificationEssentially, objective lenses can be categorized in to three main categories based on their magnification power. These include: low magnification objectives (5x and 10x) intermediate magnification objectives (20x and 50x) and high magnification objectives (100x).Apart from the differences in their magnifications, objective lenses are also different on how they are used. For instance, with a high magnification lens (100x) immersion oil is often used to obtain high resolving power. This is not the case with lower magnification objectives. Classification based on Aberration CorrectionEssentially, with regards to chromatic aberration correction, there are two main levels of correction. These include the achromatic ad apochromatic. Achromatic objectives are the simplest, least expensive and most common objectives used. These objectives are designed to correct for chromatic aberration in both the red and blue wavelengths. They are also corrected for spherical aberration in the green wavelength.The main weakness with this type of objective is that there is limited correction when it comes to chromatic aberration as well as the lack of a flat field of view. These issues reduce objective performance of these objective lenses. These lenses are particularly well suited for monochromatic applications. With apochromatic objectives, there is higher precision. These objectives are chromatically corrected for red, blue and yellow.With apochromatic objectives, there is also spherical aberration correction for two and three wavelengths in addition to a higher numerical aperture and long working distance. Because of their better design, apochromatic objectives are ideal for white light applications. Refractive and Reflective Objectives LensesThe refractive objectives are the most common objectives. With refractive objectives, light is bent (refracted) by the optical elements, which are designed in a manner that reduces back reflections thereby improving the overall light passing through. These type of objectives are often used in applications that require resolution of highly fine details. For refractive objectives, designs may range from two elements in the basic achromatic objectives to fifteen elements in plan-apochromatic objectives.As for reflective objectives, the typically use reflective/mirror based design. While this objectives may not be as common as refractive objectives, they can overcome a number of problems found in the design of refractive objectives.For instance, the design of reflective objectives incorporates a primary and secondary mirror system that helps in magnify and relay the image. With this system, the reflective objectives avoid the similar aberration experienced in refractive objectives given that light is reflected any metallic surfaces. With reflected objectives therefore, no additional designs are necessary to overcome aberrations. On the other hand, reflective objectives also have an advantage in that the produce higher light efficiency and better resolving power, which is excellent for fine detail imaging.Here, the system is largely dependent on mirror coating rather than the glass substrate. Lastly, reflective objectives have an advantage over refractive objectives in that they allow for working deeper into either the ultra-violet or infrared spectral regions given that they use mirrors.Microscope Objective LensesSpecification (Understanding Labeling)Specifications of any objectives are listed on the body of the objective. It is important to understand what the labeling means if one is to select the right objectives for their intended purpose.Specifications include: Objective standard - Such objective standards as DIN or JIS will be listed on the body of the objective depending on the type of standard. This shows the required specification present in the system. For instance, the DIN, which is the most common standard, has 160mm distance from objective frange to the frange of the eyepiece while JIS has 170mm distance. Magnification - On the objective, this is usually denoted by an X next to a numeric value (100X, 10X etc). On the other hand, objectives will also have a colored band around the circumference of the objective that indicates the magnification of the objective. For instance, a yellow band around the objectives (lower part of the objective) indicates that it is a 10x objective. Numerical aperture (NA) - numerical aperture refers to the function of focal length and entrance pupil diameter.  This is usually labeled next to the magnification of the objective (1, 1.30 etc) A large numerical aperture (more than 1) means that that immersion oil may have to be used given that the highest NA that can be achieved without immersion oils (in air) is NA of 1. This labeling is therefore important in that it directs the user on how to use the objective for better quality images. Cover slip thickness - denoted by a number (such as 0.17mm) the cover slip thickness is labeled on the objective to note the type of cover slip that should be used. A cover slip changes the way light is refracted from the specimen. Therefore, it is important to ensure that the right cover slip is used in order to produce good quality image. Quality correction - Quality correction such as achromatic, apochromatic, plan and semi-plan are often denoted on the objective in order to show the design of the objective. Plan and semi-plan objectives (also referred to as microplan, planar or semi-planar) correct for field curvature. Field curvature often results in blurred images and correction for this helps produce good quality images. Whereas plan objectives correct better, allowing for better display (over 90 percent) of field flat, semi-plan objectives produce about 80 percent.ConclusionToday, there are different types of microscopes intended for different applications. The techniques will largely depend on the type of objectives used, given that different types of objectives provide different results. For this reason, it is important to have a good understanding of the different types of objectives, their strengths and weaknesses as well as the type of specimen they are ideal for.For instance, where as reflective objectives have better features that make them superior to refractive objectives, users will also realize that they are both well suited for different applications. Therefore, having a good understanding of the different types of objectives is important if the user is to have a good viewing experience.Check out our Barlow Lens Buyer's Guide.Return to Compound Light MicroscopeReturn to Parts of a Compound Light MicroscopeReturn to Microscope ResolutionReturn to How does a Microscope Work?Return from Objective lenses to MicroscopeMaster Information homeFind out how to advertise on MicroscopeMaster!FacebookTwitter

Oct 25, 22 03:44 PMBetaproteobacteria is a heterogeneous group in the phylum Proteobacteria whose members can be found in a range of habitats from wastewater and hot springs to the Antarctic. Read more here.Read More