Sizing of Objects Quantitation is finding out things about the specimen that we can assign exact numbers to. This falls into two areas commonly, size and light amount. Size is the most used area but light amount can be quite useful. The most common size application is measuring the length of a specimen. Usually this is done with an eyepiece reticule.
Reticules come in all sizes and shapes.
They are used for routine specimen length measurements and for quite exotic types of measurements. In my experience if the application is simple reticules work well. The more exotic the application, such as projective stereo measurements, they work less well. Usually a reticule is place in the right eyepiece since, in most heads, the right eyepiece doesn't move. This means that only the right eye sees the reticule and the image.