What is thepurposeof the objectivelens inalightmicroscope

Microscope objective lenses are a classic example of optics in our lives. The function of the microscope is to enlarge objects our eyes cannot see. Unlike telescopes which enlarge far away objects, the sample observed by the microscope is close to the lens. Microscopes also correct aberration, which otherwise would lead to blurry images. Achromatic (doublet) lenses only correct for aberration of two wavelengths of light whereas apochromatic (triplet) lenses correct for 3 or more wavelengths.

Hi everyone, I've made a simple excel spreadsheet calculator for eyepiece Mag and exit pupil size it also allows Barlow magnification to be calculated.

Objectivelensmicroscopefunction

All I was trying to say is that when Barlow mag is blank or zero Excel shows a division by zero error, so if you fill 1 in the Barlow mag column that will resolve it. 🙂

All I was trying to say is that when Barlow mag is blank or zero Excel shows a division by zero error, so if you fill 1 in the Barlow mag column that will resolve it. 🙂

Typesof microscopeobjectives

One of the factors that go into designing an objective lens is the magnification. The colored bands on the outside of the microscope indicate the magnification of the lens. The standard magnification bands are as follows: red band = 5x, yellow = 10x, green = 20x, blue = 40-60x, white = 100x. Thus, if a lens has a green and yellow band, the magnification would be 30x.

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Microscopeparts

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I just thought some newer members might also get some benefit from it. You won't need to have excel on your device to be able to use it as it will work in your Google Chrome browser window.

MicroscopeObjectives magnification

Hi, many thanks and I really appreciate your kind comments but Ill just be happy if a few newcomers find it a useful when they're considering buying eyepieces as that's the reason I made it for myself.

Useful for calculating exit pupil. You might want to default the Barlow mag value to 1 so that you dont get DIV/0 errors.

No, I hadn't seen any calculators for exit pupil so decided to make my own. Just thought Iwhilst I was doing it that I'd share it with anyone who may want to use it.

Stagemicroscopefunction

Another factor to consider in designing an objective lens is the working distance (WD). This is defined to be the distance from the front of the objective to the sample when in sharp focus. Working distance is related to the numerical aperture (NA) which is calculated by the formula NA = n * sin(θa), where n is the index of refraction. When in air, n = 1. To obtain a greater refractive index and increase the numerical aperture, sometimes the objective is immersed in a liquid such as oil or water. While aberration, magnification, working distance, and numerical aperture are not the only variables to consider when designing a microscope, they are key characteristics that one should look for.

Aimsof microscopepractical

What is objectivelens inmicroscope

I could do the math on the phone but as I'm considering several eyepieces in the future it's nice to be able to see at a glance up to 10 possibilities at the same time and compare them. No point in having focal lengths to close together is there?

BTW, have you seen the calculators that FLO have created at https://astronomy.tools/calculators/magnification ? I am not sure they have a calculator for exit pupil but there is mention of exist pupil on this page

Useful for calculating exit pupil. You might want to default the Barlow mag value to 1 so that you dont get DIV/0 errors.

I posted this purely out of my desire to help others where I can and because I hadn't seen any readily available to newcomers.

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BTW, have you seen the calculators that FLO have created at https://astronomy.tools/calculators/magnification ? I am not sure they have a calculator for exit pupil but there is mention of exist pupil on this page

You simply type in your objective  or mirror diameter in mm and the focal length of your scope in mm and the focal length of the eyepiece that you are looking at or considering and the sheet will calculate your magnification and exit pupil size. If you are using a barlow type the mag of the barlow (eg for a 2x barlow type 2 in the box under Barlow mag X) and the sheet will calculate the revised magnification and the size of the exit pupil too.