Reticles are sometimes also called "eyepiece micrometers". They are clear circular glass inserts with a scale inscribed on them. The reticle or eyepiece micrometer sits right at the focal plane inside the eyepiece lens of the microscope and allows the investigator to make accurate measurements of specimens.

Reticles come in many varieties and in different diameters.Most common is a straight line reticle. Other types available include plain cross line, square grids and circular patterns. You will have to supply the reticle diameter to be assured of one that will fit.

Model:C4	Model:C7	Model:C5

Mounting the reticle is a somewhat critical operation. They are relatively simple to install but since they sit right on the focal plane, any dust on the reticle will be quite apparent when looking into the microscope. You can use a small spanner wrench or simply a very small flat edge screwdriver. Insert the blade into the notch in the ring and spin it out. Using compressed air to blow out any dust after installing your reticle is recommend.

Model:C1

The "actual" distance between any two marks on the reticle are a function of the objective lenses only. The best way to calibrate your reticle is to use what is called a stage micrometer. This is a slide that has tiny marks of a known dimensions inscribed on it. By making a comparison of the marks on the stage micrometer to the marks on the reticle, one can establish the actual value for each mark on the reticle.

When you look into your eyepiece lens, the markings will always be the same but the size of the image superimposed under them will get larger with more magnification.For the most accurate results, you should calibrate your reticle using a stage micrometer for each objective lens.

For a reticle that is 10mm long with 100 divisions (as shown above), each division was found to represent the following distances:

The proper way to calibrate a reticle with a stage micrometer is to line up the left edges of each, then see where the lines converge again.

Many people purchase a separate eyepiece lens for their reticle so when they want to use their microscope without it, they simply interchange the lenses.