how is the total magnification of a microscope determined

The magnification of the objective time the magnification of the eyepiece is the simple answer. That has to be multiplied by the addition of any inserts that change the magnification such as an Otivar* or polarized light analyzer that changes the tube length or has optics that modify the effective tube length.

For example a 10x eyepiece and 5x objective designed for a 160 mm tube that are only 100 mm apart will have a magnification about 10 X 5 X100/160 or 31.25x. If a 1.6x Optivar were added the magnification would be back to 50x.

If you are working with a photograph you must allow for the protection and or optics involved there as well.

In reality the only way to know for sure is to view something of a know size with an eyepiece that can can measure the size or measure in a photograph and calculate the overall magnification. That is due to there being slight variations in the magnification of objectives, eyepieces and all the other variables that you can’t know with certainty.

With enough care the size of an object under a microscope can be measured to very close tolerances. The closer the tolerances the harder the job.

Magnification is the process of enlarging something only in appearance, not in physical size. Magnification is also a number describing by which factor an object was magnified. When this number is less than one it refers to a reduction in size, sometimes called minification.

Typically magnification is related to scaling up visuals or images to be able to see more detail, increasing resolution, using optics, printing techniques, or digital processing. In all cases, the magnification of the image does not change the perspective of the image.

Total Magnification is determined by multiplying the eyepiece power (usually 10x) by the objective lens in place.
For example, a 10x eyepiece and a 4x objective yields a total magnification of 40x (40 power).

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ou multiply the magnification of the eyepiece by the multiplication of the lens you’re using.

So for example, if the eyepiece is 10x, and the lens is 40x, that will create a magnification of 400x.

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.

how is the total magnification power of a compound microscope determined
how is the total magnification of a microscope determined