HPS 113 stereo microscope, 20x and 40x magnification and photo tube

This refers to the magnification factor of a single microscope lens. A lens with the number 40 is referred to as a scale of 1:40 or simply a factor of 40 times. If you multiply the lens factor by the eyepiece factor, you get the magnification.

Describes the position in which you look through the eyepiece, for example at 45° or straight.

Used to hold colour filters for contrast enhancement.