Microscope objectives

An introduction to 'infinity' corrected microscope objectives.

Contents

Mechanics

For integration purposes the physical size and shape of an objective may be important. Due to the popularity of using different objectives on the same instrument, the major manufacturers tend to standardize the mounting threads and parfocal distance (i.e. the distance from the objective flange to the image plane):

Make Standard thread Parfocal distance (mm)
Leica M25x0.75 45
Mitutoyo M26x36TPI 95
Nikon M25x0.75 60
Olympus W20.32x0.706 (RMS) 45
Zeiss M27x0.75 45

The major manufacturers now release detailed 2D drawings which can be used to produce 3D CAD models if needed. For example here's a drawing for the Nikon 100x1.35 Silicone objective:

Nikon_MRD73950_mechanics.png
Mechanical drawing for the Nikon 100x1.35 Silicone objective (MRD73950).