Uppendahl prism

The erecting system consists of three partial prisms made of optical glass with a high refractive index cemented together to form a symmetric assembly and is[2] used in microscopy as well as in binoculars technology.

The Trinovid series binoculars were introduced in 1958 and used at the time patented moving internal optical lenses between the ocular lens group and the prism assembly within the housing for focusing.

Bausch & Lomb Elite and Browning 7×35 binoculars, both made in Japan during the late 1980s to early 1990s, also used Uppendahl prisms.

[7] The Leica Geovid R (laser) rangefinder binoculars series and 7×24 Rangemaster monocular using a (modified) Uppendahl prism system were still commercially available.

An advantage of this prism system is that the light beam only passes two transitions between air and glass, which minimizes losses in the form of Fresnel reflections.

[10] In order to achieve maximum light transmission, the Uppendahl prism system should be provided with an anti-reflective coating on the incidence and exit surfaces.