Here the text of The Zeiss page and some images:
The powerful photojournalist – fast, compact, accurate
The C Sonnar T* 1.5/50 ZM lens is the modern technological reincarnation of the classical Sonnar 1.5/50, the fastest standard lens of its time, for the Contax II rangefinder camera.
It is fast, very resistant to flaring and unusually compact – therefore the “C†in the lens name. With its well controlled distortion, the lens produces a very accurate representation of objects. It can take the same filters which fit the ZM wide angle lenses with 28, 25 and 21mm focal lengths. This is a very versatile lens for photojournalistic work in general and for available light photography in particular.
Technical Specifications
Focal length: 50 mm
Aperture range: f /1.5 – f/16 (1/3 f-stop)
No. of elements/groups: 6/4
Focusing range: 0.9 m – infinity
Image ratio at close range: 1:15
Coverage at close range: 37 x 55 cm
Angular field, diag./horiz.: 46°/38°
Filter: M 46 x 0.75
Weight: 250 g
Dimensions: ø 56 mm, length 45 mm