A Bauernfeind prism is a type of reflecting prism used to deviate a beam of light by 45° to 60°, depending on its construction, while neither flipping nor rotating the image.
A Bauernfeind prism with 45° beam deviation is also known as a half-penta prism or semipentaprism.
A Bauernfeind prism is used together with a Schmidt roof prism to form a Schmidt–Pechan prism.
Applications
The Bauernfeind prism is commonly used in microscope tubes and in geodesy to deviate the path to the eyepiece in order make the device more ergonomic.
Chinese 
English
Chinese
English