How to Determine Magnification of a Microscope
- 1). 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.
- 2). 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.
- 3). 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.
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