Carl Zeiss Jena Sonnar T 1: 1.5 F = 5cm is a fast normal single-layer coated lens for rangefinder cameras Contax I - Contax III, manufactured at the Carl Zeiss Jena factories in Dresden.
Designed in 1932 by Ludwig Bertele.
The real focal length of this lens is 52.54mm
After World War II, a lot of captured CZJ 50 / 1.5 lens blocks were exported from Germany to the USSR on account of reparations (technology descriptions, Schott equipment, as well as various construction materials, including optical glass, were also exported).