LM - Microscope Eyepiece Magnification

Standard 10x eyepieces (oculars) are supplied with all ProSciTech microscopes. Other magnifications are available. 15x and 20x eyepieces are commonly used in stereo microscopes, these increase magnification. The objective is the more important lens group; eyepieces can only enlarge existing information projected by the objective.

All our eyepieces are high quality, plan achromatic lens and can be placed in other microscopes (brands and types), be they stereo or compound microscopes ‐ if they have the right diameter. Our stereo microscopes use 30mm diameter eyepieces. Confusingly, some brands use 30.5mm eyepieces. The common standard for compound microscopes is 23.2mm, but some manufacturers use either of the larger size eyepieces on compound microscopes.

It can be hard to tell the difference between a $50 and $400 eyepiece; brand name tags are very expensive.

Final magnification in microscopy depends on several factors. In stereo or macro systems the magnification at the eye is the magnification of the objective multiplied by that of the eyepiece. If an additional lens is added to the front of the objective, both, photo and viewing magnifications, whereas the use of different eyepieces changes viewed magnifications only. Photo magnification is subject to other, additional factors.

Final magnification:

Compound microscopes, objective x eyepieces = Final magnification
Zoom stereo microscopes, objective x eyepieces x zoom range (min and max) = Final magnification

Example:
The standard OXTL series microscope is equipped with a 1x objective, 10x eyepiece and has a zoom range of 0.7x ‐ 4.5.

Minimum magnification = 1 x 10 x 0.7 = 7x 

Maximum magnification = 1 x 10 x 4.5 = 45x

This OXTL microscope has standard magnification range of 7x ‐ 45x