The Zeiss Hologon is an ultra wide-angle f=15mm f/8 triplet lens, providing a 110° angle of view for 35mm format cameras.
The Hologon was originally fitted to a dedicated camera, the Zeiss Ikon Contarex Hologon in the late 1960s; as sales of that camera were poor and the Zeiss Ikon company itself was going bankrupt, an additional 225 lenses were made in Leica M mount and released for sale in 1972 as the only Zeiss-branded lenses for Leica rangefinders until the ZM line was released in 2005.
[2] As built, the symmetrical design for the Hologon 8/15mm by Glatzel provided excellent correction of coma, spherical and chromatic aberration, astigmatism, and curvature of field; the main fault was vignetting due to the cos4 law, which was corrected by supplying a graduated neutral density filter to make the exposure more even across the film frame.
[9] Typically, a pistol grip is affixed to the Hologon camera to avoid inadvertently taking pictures of the photographer's fingers.
[12][13] Because of the low production numbers and unique focal length, some lenses have been separated from the Contarex Hologon and adapted to Leica mount.
Zeiss claimed that contrast had been improved by moving the rear element closer to the film plane.