Figure 4-21. Erecting system using two double right-angle Abbe prisms.

TM 9-258

(3) Amici or roof-angle prism. When used in

secured by reflection on two of its surfaces. It can be

an elbow telescope, this single prism (fig 4-11) serves as

mounted securely and thus is suitable for telescopes are

an erecting system as well as a right angle prism. By its

mounted on gun carriages. Combined with a rotating

use the light rays are diverted through the right angle of

prism and a right-angle prism it is used in the erecting

the telescope and the erection of the image is

system of panoramic telescopes (fig 4-22).

4-23