Soviet factory KMZ produced several lenses that used the Sonnar formula: The KMZ Jupiter 3, Jupiter-8, and Jupiter-9 are direct copies of the Zeiss Sonnar 1:1.5 50 mm, 1:2.0 50 mm and 1:2.0 85 mm respectively. A zoom lens derivative of the Sonnar, the Vario-Sonnar also exists, in which a number of lens groups are replaced with floating pairs of lens groups. The Vario-Sonnar is a Carl Zeiss photographic lens design named in relation to the Zeiss Sonnar. This lens type has a variable focal length which can replace a series of lenses for a certain picture format. See also Biotar Tessar Planar Biogon Hologon Photographic lens design External links Vario-Sonnar diagram References Antique and Classic Cameras Sonnar Lens Types for Leica mount Photographic lens designs Sonnar