Description

Stage graticules (also known as stage micrometers), supplied in a convenient microscope slide format, are used to calibrate microscope eyepiece graticules. Eyepiece graticules give a reasonably accurate gauge of viewed object sizes, but, owing to differences in the optical systems of different objectives and eyepieces, calibration is needed for accurate work. This is simply done by placing the stage graticule on the microscope stage and viewing it through the microscope. Comparision of the eyepiece graticule with the stage graticule enables either a correction factor to be calculated or, perhaps, in bespoke systems, the optical spacing to be adjusted to eliminate the magnification error.