The Basics of Calculating Total Magnification

by Andy on June 3, 2009

Magnifying Glass It’s fairly well known that magnification is the process of making an object appear larger. The purpose is usually to see detail that is impossible or difficult to see with the naked eye.

The total magnification depends on a couple different pieces of the microscope including the eye pieces, zoom body and any lens including auxiliary and objective lens.

It’s important to remember that any magnification over 1.0X will make the image larger, while any magnification under 1.0X will make the image smaller. So if a microscope has a 1.5x auxiliary lens then the magnification will increase by half i.e. something that is 10cm long will appear 15cm long.

Do the following to get total magnification:

  1. Take the initial objective lens and multiply it by the auxiliary lens to get the total lens magnification
  2. Take the lens magnification and multiply it by the eyepiece magnification
  3. Take this number and multiply by the magnification of the body (which on a zoom microscope is a range).

For example, the Luxo 23711 binocular stereo-zoom microscope has a .7X-4.5X zoom body, 10X eyepieces, no auxiliary lens and no objective lens. The magnification for the microscope as it comes from the plant is 7X-45X. You get this number by multiplying all the magnification components together. If you added the 1.5X auxiliary lens, you would have a magnification range of 10.5X-67.5X (7X-45X * 1.5X = 10.5X-67.5X).

Wondering about diopters too?

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