Penta prism can deviate an incident beam without inverting or reversing to 90o. The deviation angle of 90o is independent of any rotation of the prism about an axis parallel to the line of intersection of the two reflecting faces. It is commonly used in Plumb Level, Surveying, Alignment, Rangefinding and Optical Tooling.

Specification for standard penta prism:


Material:  BK7 Grade A optical glass
Dimension Tolerance: +0,-0.2mm
Flatness:  λ/4 at 632.8 nm
Surface Quality: 60-40 scratch and dig
Clear Aperture: >80%
Bevel: 0.2 mm to 0.5 mm x 45o


Reflectivity: R > 95% ( for design wavelength) per face