The objective in decent condition considering the age.

Faults:

Small damage on the filter thread (still works for filter/hood mounting)

some dust and green discoloration on the edges of the lens (I doth think it's a fungus and it's not spreading)

air bubble in the back element (has no visible effect on the photos and is common for the era)

Good things:

The focus is very smooth and the aperture is pretty smooth

Center is sharp

The objective was adopted on helicoid to work on modern cameras with m42 to your system adapter (I used it on panasonic s5 and it focuses to infinity but might need adjustment depending on your system).

The adapter can be removed easily without damaging the lens by just pulling the lens out with a lot of force (there is a layer of glue and tape holding the lens in place)

Format: 35mm rangefinder

Lens mounts: Contax I-III (CRM)

First year of production: 1932

Optical design: 7 elements in 3 groups

The Carl Zeiss Jena Sonnar T 50 mmf/ 1.5  is a standard fast lens with a single-layer coating for the rangefinder Contax I – Contax II cameras produced at the Carl Zeiss Jena works in Dresden.

It was designed by Ludwig Bertele in 1932.

The real focal length of the lens is 52.54 mm.

Focal length 50mm

Max. aperture f/1.5

Min. aperture f/22

Blades 13

Min. Focus (m.) 1

Filter Ø (mm.)40.5

Weight (gr/oz) 160/5,6

Length (mm/in) 42/1,7