Global InformationPerger prism information
A Perger prism or Perger–Porro prism system is a prism, that is used to invert (rotate by 180°) an image. The special feature of this prism is that, like a traditional double Porro prism system, it manages this with only four beam deflections and has neither a roof edge with the accompanying phase correction problems, a mirrored surface or an air gap. However, in contrast to the traditional double Porro prism, it leads to a significantly reduced eyepiece/objective axis offset. The reduced beam offset allows for slimmer, more straight binocular housings usually found in roof prism binoculars. Complicating production requirements make high-quality roof prism binoculars relatively costly to produce compared to in optical quality equivalent Porro prism or "Perger–Porro prism system" binoculars.[1][2][3]
Dr. Andreas Perger patented the inversion system in 2011, and it was initially used in the Geovid HD laser rangefinding binoculars (2013 third generation) from the manufacturer Leica. This manufacturer uses the "Perger–Porro prism system" designation for this binoculars line, which features curved (banana shaped) binocular barrels.[4][5][6]
- ^ Thompson, Robert Bruce; Thompson, Barbara Fritchman (2005-06-24). Astronomy Hacks, chapter 1, page 34. "O'Reilly Media, Inc.". ISBN 9780596100605. Retrieved 2009-11-03.
- ^ Why do the best roof-prism binoculars need a phase-correction coating?
- ^ Binocular Optics and Mechanics Chapter from Binocular Astronomy by Stephen Tonkin
- ^ European Patent EP2463692A1 Prism
- ^ Leica Geovid The perfected symbiosis of viewing and distance measurement
- ^ Leica Geovid 8×42 HD-R (Typ 402)