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A Dove prism is a type of reflective prism which is used to invert an image. Dove prisms are shaped from a truncated right-angle prism. The Dove prism is named for its inventor, Heinrich Wilhelm Dove. Although the shape of this prism is similar to the shape described by a Dovetail joint, the etymology of the two is unrelated.
A beam of light travelling parallel to the longitudinal axis, entering one of the sloped faces of the prism undergoes total internal reflection from the inside of the longest face and emerges from the opposite sloped face. Images passing through the prism are flipped , and because only one reflection takes place, the image is also inverted but not laterally transposed.
Refraction at the entrance and exit surfaces results in substantial image astigmatism when used in convergent light. Thus the Dove prism is used almost exclusively for images appearing at infinity.
If the flat hypotenuse surface of a Dove prism is cut into a roof shape, the result is an Amici roof prism.