Invented by H.W. Dove, Dove Prisms are also known Reversion prisms. When the prism is rotated about its length axis, the image viewed through the prism rotates at twice the prism rotation rate. This is an unusual and sometimes useful property for special applications. Entry and exit faces are anti-reflection coated.
Wedge prism is an optical element with plane-inclined surfaces, usually the faces are inclined toward one another at a very small angles. It diverts light toward its thicker portion. Wedge prisms can be used as isolating components. Wedges may also be used to produce a small deviation which doesnt allow return to source.