When an object is sighted through the telescope, an objective lens and a collective lens in the objective
tube form an inverted image of the object on the reticle. After passing through prisms in the articulated
joint assembly, the image is erected by the erector assembly and projected through two offset prisms to
the eyepiece assembly. The offset prisms raise the eyepiece 2 inches and displace it 15 degrees to the right
for the convenience of the gunner. The outside surfaces of all optical elements, except the reticle blank
and the reflecting surfaces of the prisms, are covered with a thin coating of magnesium fluoride. This
coating increases light transmission and minimizes internal reflections.