功能

• Reflect twice with a mirror to convert the mirrored reflection into the same upright image as the object.
• Before cameras went digital, pentaprisms were used to bend light rays from objects at right angles so that the image was not mirror symmetric.
• It is also used as a right-angle reference for laser markers.
• Even if the angle of incidence to the prism changes, it always emits at 90 degrees to the incident ray.
• Using the internal reflection of the prism is more compact than using two mirrors, because there is no angular deviation.
• * If you wipe the black paint with solvent, it may dissolve.
• * Reflection of the inner surface of the prism by Al coating has a reflectivity loss of about 12% on one surface and 23% on two surfaces.
• * The input/output efficiency is about 77%.