If you are interested in buying various types of objective lenses for your microscope in the classroom, laboratory, research facility, or any other purpose, ACCU-SCOPE can provide the products you are looking for. Contact us today to learn more about our objective lenses and other microscope accessories.

Numerical aperture ofcondenserlens

The high-powered objective lens (also called “high dry” lens) is ideal for observing fine details within a specimen sample. The total magnification of a high-power objective lens combined with a 10x eyepiece is equal to 400x magnification, giving you a very detailed picture of the specimen in your slide.

Knowledge Center/ Application Notes/ Optics Application Notes/ Custom Bandpass Filter using Shortpass and Longpass Filters

Numerical aperture ofmicroscope formula

Bandpass filters are optical filters that allow transmission of a specific range of wavelengths, or band, while blocking other wavelengths. Many off-the-shelf bandpass filter options are available, but when an application has specific requirements for bandwidth or center wavelength not readily available, Longpass and Shortpass filters can be stacked creating a customized bandpass filter. Longpass filters are optical filters that reflect short wavelengths while transmitting, or passing, long wavelengths. Conversely, Shortpass filters transmit short wavelengths but reflect long ones. Examples of both are represented in Figure 1.

The oil immersion objective lens provides the most powerful magnification, with a whopping magnification total of 1000x when combined with a 10x eyepiece. But the refractive index of air and your glass slide are slightly different, so a special immersion oil must be used to help bridge the gap. Without adding a drop of immersion oil, the oil immersion objective lens will not function correctly, the specimen will appear blurry, and you will not achieve an ideal magnification or resolution. Oil immersion lenses are also available from some manufacturers in lower magnifications, and provide higher resolution than their "high dry" counterparts.

Numerical aperture of objective lens

Numerical aperture of4xObjective lens

It is important to always use the correct immersion media (e.g. air, water, oil, etc.) that is specified by your objective lens.

H(λ) can be denoted as the transmission of a filter and λ as the wavelength. Figure 2 shows a Heaviside model of the LWP graph from Figure 1.

Numerical aperture ofoil immersionlens

The low power objective lens has more magnification power than the scanning objective lens, and it is one of the most helpful lenses when it comes to observing and analyzing glass slide samples. The total magnification of a low power objective lens combined with a 10x eyepiece lens is 100x magnification, giving you a closer view of the slide than a scanning objective lens without getting too close for general viewing purposes.

Numerical aperture of 100x objective lensformula

Most compound microscopes come with interchangeable lenses known as objective lenses. Objective lenses come in various magnification powers, with the most common being 4x, 10x, 40x, and 100x, also known as scanning, low power, high power, and (typically) oil immersion objectives, respectively. Let’s take a closer look at each of the different magnifications of objective lenses and when you would use them.

Stacking Longpass and Shortpass filters can quickly create a custom solution for selecting a specific bandpass and is an ideal alternative in scenarios where an off-the-shelf bandpass filter doesn't meet the application's requirements or a customer filter design is too expensive or has too long of a lead time.

JavaScript seems to be disabled in your browser. You must have JavaScript enabled in your browser to utilize the functionality of this website.

Numerical aperture of10xobjective lens

The transmission graphs are very similar to Heaviside functions (denoted as H(λ)) in mathematics. As shown in Equation 1, Heaviside functions are specialized piecewise functions that have a value of one for a certain domain and zero for the rest. The domain is determined by the constant x.

There are several other objective lens magnifications available with utility for particular applications. The 2x objective, widely used in pathology, has only ½ the magnification of a 4x scanning lens, thus providing a better overview of the sample on the slide. The 50x oil immersion objective, often used in place of the 40x objective, is used as a gold standard for observing blood smears. The 60x objective, often available in either dry or oil immersion, provides 50% greater magnification than a 40x lens. The 60x dry is sometimes chosen over a 100x oil immersion lens for higher magnification without the need to use immersion oil.  Finally the 100x dry objective doesn’t need immersion oil to deliver high magnification (still 1000x when combined with 10x eyepieces). However, the numerical aperture (an indication of resolving power of an objective) of a 100x dry objective is much lower than that of a 100x oil immersion objective and, as a result, the ability of the lens to resolve fine details in the specimen is much lower, too.

A custom optical bandpass filter can be made by using at least two filters. This is conceptually very similar to multiplying Heaviside functions in mathematics. In order to obtain a rectangular function from 540 to 545, the two Heaviside functions must be multiplied together as shown in Equation 2 and Figure 3.

Numerical aperture of40xobjective lens

What is achieved through multiplication in mathematics is achieved physically by layering two or more optical filters. When layering multiple optical filters, light propagates through one filter and into the next. Because each filter transmits certain wavelengths, layering allows for the transmission of a customized band of wavelengths.

A scanning objective lens provides the lowest magnification power of all objective lenses. 4x is a common magnification for scanning objectives and, when combined with the magnification power of a 10x eyepiece lens, a 4x scanning objective lens gives a total magnification of 40x. The name “scanning” objective lens comes from the fact that they provide observers with about enough magnification for a good overview of the slide, essentially a “scan” of the slide. Some objectives with even lower power are discussed in Specialty Objectives below.

Please select your shipping country to view the most accurate inventory information, and to determine the correct Edmund Optics sales office for your order.