Dove prisms may invert, reverse, or rotate an image based on which face the light is incident on, so they are also called image rotation or reversion prisms. Dove prisms can be thought of as right-angle prisms with the triangular apex removed, which reduce the weight of the prism and stray internal reflections. They introduce astigmatism when used with converging light, so we recommend using them with collimated light.Additionally, Dove prisms affect the polarization state of light transmitted through them. When light is incident on the longest face, the Dove prism acts as a retroreflector or a right-angle prism. The light exits parallel to the input light (independent of the incidence angle) and is inverted by 180°. In situations with limited space or where more convenient mounting options are needed, the Dove prism can replace a retroreflector or right-angle prism.