What Is the Diameter of the Low Power Field of View of a Microscope?

The diameter of the field of view of a typical compound microscope that uses a low power objective at 10x magnification is approximately 2 millimeters, or 2,000 micrometers. One millimeter is roughly equivalent to 1/25th of an inch, and 1 mm is 1/25,000th of an inch.

Microscopes are optical devices used to view and magnify objects that are too small to be seen by the naked eye. Generally, compound light microscopes are composed of two lens systems: ocular and objective. The ocular lens pertains to the eyepiece, which has a constant magnification of 10x. The objective lenses provide shifting magnification power for the eyepiece.

Compound microscopes usually have four objective lenses that are used for scanning, low power magnification, high power magnification and oil immersion. The low power objective lens has a magnification of 10x. To calculate the total magnification of a specimen under low power, the ocular magnification of 10x is multiplied by 10x to obtain 100x. This magnification value determines the diameter of the field of view when the low power objective is used.

A microscope’s field of view refers to the diameter of the circular optical light that is visible when viewing an object under the microscope. This value forms an inverse relationship with magnification, which means that increasing the magnification results in the reduction of the field of view. Using a low power objective lens under 100x total magnification, the field of view can be measured by placing a transparent mm ruler under the microscope and counting how many mm are covered by the diameter of the circular optical light. The precise value is equal to 1,780 mm, which is generally rounded up to 2,000 mm.