Dove prism is a kind of reflection prism used for image reflection.Dove prisms are formed by truncated rectangular prisms.A beam of light enters one of the slanted faces of the prism, fully reflects from inside the longest (bottom) face, and then exits from the opposite slanted face.The image through the prism is flipped, and since only one reflection occurs, the handedness of the image is reversed.Dove prisms have an interesting property that when they rotate along the vertical axis, the transmitted image rotates twice as fast as the prism.It is very important that applications use parallel or collimating beams and keep the large square reflector very clean.Another application is as an inverse. Dove Prism Specifications Material BK7, UV Fused Silica, Sapphire, ZnSe, Caf2, Si, Ge, etc. Size 2mm-300mm Size tolerance +/-0.02mm or customer request Clear Aperture 90% S/D 60-40 40-20 20/10 10/5 Flatness 1/10lambda at 632.80nm Chamfer 0.25mmx45 Angle tolerance