Binoculars with roof-like prisms in their optical construction provide compact design due to straight-line position of eyepieces and objective lenses. They are more expensive due to complex manufacturing and are providing many advantages for more demanding users. They are less sensitive to impacts and abrasions and are incredibly impervious for water and dust entering the construction. They are usually purged with nitrogen or argon gas, which also helps to eliminate internal glass fogging. Compared to Porro prism binoculars, they are more likely to withstand extreme weather conditions. Very good ergonomic design of this straight-line construction makes them less difficult to hold in hands and eases your portability immensely. But compared to Porro prism binoculars, this construction makes light transmission less permeable and thus providing darker and less sharp images.
Roof prism binoculars are divided in two main groups with the following types of prisms:
Roof prism binoculars according to the types of prisms
Schmidt – Pechan
Abbe – König
(+) compact
(+) lightweight
(+) good ergonomics
(+) easy handling
(+) central focusing
(+) waterproof
(+) adjustable eyepieces
(-) lower light transmission rate compared to Abbe-König
(+) compact
(+) better light transmission
(+) easy handling
(+) central focusing
(+) waterproof
(+) adjustable eyepieces
(-) expensive
(-) longer design
The main difference between both types of binoculars with Roof prism is that those with Schmidt – Pechan prisms tend to be smaller and less expensive, while those with Abbe – Köning prisms tend to have better light transmission rate and have a longer design.
Video presentation of Schmidt/Pechan Prism Binoculars
Optics Trade debate about Schmidt-Pechan vs Abbe-Koenig prism
