Roof Prism Design

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.

Nevertheless the roof prism design s appeal was so great that manufacturers went all out to perfect it. Roof prisms enable slim binoculars. While the roof prism design is inferior to the porro prism in its basic form roof prisms often have higher quality glass and stricter engineering controls versus cheap porro prism binos. A roof prism also called a dach prism or dachkanten prism from the german.

However the costs of producing roof prisms are higher than those for porro prism binoculars. Roof prisms in binoculars. The porro prism design was simpler and more light efficient and its images showed better contrast. Dachkante lit roof edge is a reflective optical prism containing a section where two faces meet at a 90 angle.

Today roof prisms dominate the top end birding binocular market. There are two prisms and these meet at a 90 angle with the shape looking similar to the roof of a house. Roof prisms are the newer option. The design of the prisms means they work together to correct blurred images and let you see your target clearly.

Reflection from the two 90 faces returns an image that is flipped laterally across the axis where the faces meet. These two 90 faces resemble the roof of a building giving this prism type its name. 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.