Unar (lens)
Unar is the name of a camera lens developed by Carl Zeiss in 1900 . It is an anastigmat and consists of four individual lenses , two outer converging lenses and two inner diverging lenses, between which the diaphragm is located. In contrast to the similar aristostigmat , the anterior divergent lens is not a meniscus, but biconcave.
The Tessar is an improved successor to the Unar .
Web links
Article about the Tessar, in which the Unar is also described