# how to calculate the magnification of a microscope

how to find total magnification of a microscope?

Telescopes and microscopes typically use two lenses. The user looks through the ocular lens, or eye piece, while an objective lens on the opposite end of the device further magnifies the object under observation. Though the two devices work similarly, the process for calculating their magnification is different.

Magnification in Microscopes

The formula for the total magnification of a microscope is the objective lens magnification times the ocular lens magnification. Almost all adjustable microscopes have the magnification of each lens written on the side of the lens. If you can’t find it, look in the user’s manual for the figures. Most microscopes have an ocular lens magnification of 10. In a microscope with an ocular magnification of 10 and an objective magnification of 20, the total magnification would be 200x.

Magnification in Telescopes

The formula for total magnification of a telescope is the focal length of the objective lens divided by the focal length of the eyepiece lens. The focal length is the distance between the center of the lens and the point where it is in focus. As with microscopes, you can find this data in the owner’s manual or on the labeling of the specific device. In a telescope with an objective lens focal length of 1000 mm and an eyepiece focal length of 10mm, the total magnification would be 100x.

The magnification of a microscope describes the increase in apparent size of an object compared with its actual size. An object magnified 10 times (10X) appears 10 times larger than it really is. Total magnification is the product of the ocular lens magnification and the objective lens magnification. Magnification does not describe the quality of the image. Magnifying an object without good resolution is called empty magnification, as the image appears larger but no greater detail can be seen. Resolution typically limits the usefulness of light microscopes rather than magnification.

Record the magnification of the ocular lens in the eyepiece. The magnification of the ocular lens is typically engraved on the side of the eyepiece.

Record the magnification of the objective lens. The magnification is frequently engraved along with the numerical aperture (NA) on the side of the objective lens. Many compound light microscopes allow different objective lenses to be rotated into use on the nosepiece. Each objective lens has a different magnification.

Multiply the magnification of the eyepiece by the magnification of the objective lens to produce total magnification. For example, a 10X ocular lens and a 40X objective lens will produce a total magnification of 400X (10 x 40 = 400). Changing the ocular lens or objective lens to lenses with a different magnification will change the total magnification of the microscope. Usually, it is the objective lens that is changed to increase or decrease magnification.

Compound light microscopes use a series of lenses and visible light to magnify objects. The magnification allows the user to view bacteria, individual cells and some cell components. In order to calculate the magnification, the power of the ocular and objective lenses is needed. The ocular lens is located in the eye piece. The scope also has one to four objective lenses located on a rotating wheel above the platform. The total magnification is the product of the ocular and objective lenses.

Calculate Magnification of a Compound Light Microscope

How to Calculate Magnification of a Microscope

If you have ever been in a biology lab, then you have probably used a microscope to view slides. Microscopes help us magnify tiny objects so that you can view them more easily. This is important when you want to view an object on the cellular level. They come equipped with adjustable settings so that you can view the slides at different powers.

By AlysonNolan

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If you have ever been in a biology lab, then you have probably used a microscope to view slides. Microscopes help us magnify tiny objects so that you can view them more easily. This is important when you want to view an object on the cellular level. They come equipped with adjustable settings so that you can view the slides at different powers.

Dials on the side of the microscope adjust the magnification level.
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Step 1

Locate the power of the eye piece, which is usually 10X. It is typically written on the top of the microscope on the eyepiece.
Step 2

Determine the power of the objective that you are using to examine the slide. Typically viewing powers are 4X, 10X and 40X.
Step 3

Multiply the viewing power of the eye piece by the power of the objective used to examine the slide. For example, if the viewing power is 10X and you use the power of the objective at 10X, then the magnification is 100X.

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