From Wikipedia, the free encyclopedia
A roof pentamirror contains 3 mirrors.

A pentamirror is an optical device used in the viewfinder systems of various single-lens reflex cameras instead of the pentaprism. It is used to reverse again the laterally reversed image coming from the reflex mirror.[1]

Instead of the solid block of glass of the prism in pentaprism system, here 3 mirrors are used to perform the same task. This is cheaper and lighter, but generally produces a viewfinder image of lower quality and brightness.[2]

This optical device is often (more precisely) referred to as roof pentamirror because of the roof-like ridge.[3]

See also[edit]


  1. ^ Mike Stensvold. The Complete Idiot's Guide to Photography Like a Pro, 2002, page 26.
  2. ^ David D. Busch. Digital Photography All-in-One Desk Reference for Dummies, 2006, page 106.
  3. ^ Paul R. Yoder. Opto-Mechanical Systems Design, 2005, page 435.

External links[edit]