Roof Prism Design

The first prism has one surface that has no internal reflective qualities.

Roof prism design. To fix this it needs to be applied with a special coating such as a mirror coating in order to raise its reflectivity to limit light loss. The open bridge design has a focus mechanism close to the eyepiece with the stabilizing section towards the objectives while the closed bridge design has an enclosed focus mechanism. Roof prism design looks as if the light goes straight through. A roof prism utilizes two glass prisms to bend light via a complex pattern in order to make it compact and split it into two halves where it eventually flows back together before reaching the eye.

In both designs light passes through objective lenses that cast it onto a set of mirrors that further flip rotate and focus the image through an eyepiece and. There are several different roof prism combinations that can be used depending on the design and purpose and desired features of a roof prism binoculars. They made the offset zig zag shape of the porro prism design look as old fashioned as propeller driven aircraft. Roof edge is a reflective optical prism containing a section where two faces meet at a 90 angle.

The most common today is schmid pechan s prism system. Different styles of roof prisms can be found in binoculars but the most common types are the abbe koenig and the schmidt pechan. Built to last in a harsh environment a roof prism binoculars central portion that connects the 2 tubes is either an open bridge or closed bridge design. When light enters the prism it bounces across several angles before exiting through the opposite side extending the light s path.

Porro prism design has a jog in the light path through each barrel. These two 90 faces resemble the roof of a building giving this prism type its name. The roof prism is a more modern design that consists of two prisms cemented together in a single interior mount. To borrow one of barsness analogies think of it like a rock in the middle of a stream.

The abbe koenig is comprised of two connected prisms that form a v shape. A roof prism also called a dach prism or dachkanten prism from the german. It consists of a reflective surface with a metallic mirror vapor steam coating eg silver.