Dove Prism

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.A beam of light entering one of the sloped faces of the prism undergoes total reflection from the inside of longest (bottom) face and emerges from the opposite sloped face.Images passing through the prism are flipped , and because only one reflection takes place, the image’s handedness is changed to the opposite sense. 

Coated dove prisms feature a protected aluminum coating with black Krylon paint on the diagonals and are ideal for displaced retro reflection. They provide a U-turn for laser beams.