Amici Roof Prism

• Amici prisms are ideal for binocular and scope prisms because they maintain the visual orientation. The Amici prism is named for Italian astronomer and inventor Giovanni Amici. The Amici prism is sometimes called the "right angle roof prism" because it bends the image through a 90-degree angle.
  
  

Abbe-Koenig Prism

• The Abbe-Koenig prism is named for the inventors, Ernst Abbe and Albert Koenig. This prism is a roof prism and a right-angle prism that have been cemented together. The two faces form a 90-degree angle. The light enters one face of the prism, is reflected at the 30-degree face, then is reflected from the "roof" portion of the prism.
  
  

Schmidt-Pechan Prism

• Schmidt-Pechan prisms are common binocular prisms, especially in compact binocular designs. The Schmidt-Pechan prism is an optical combination of the Schmidt prism and the Pechan prism. The prism rotates the image by 180 degrees and is used as an alternative to the Porro prism.
  
  

Considerations

• You easily can identify a pair of binoculars that utilizes roof prisms instead of Porro prisms by the binocular design. Roof prism binoculars generally are more compact. The objective lenses, or the larger lenses on the binoculars, are in line. In Porro-prism binoculars, the lenses are offset.