This CZJ Tessar is a small silver shiny beauty. Its serial (3692001) can be traced back to a batch of 2000 lenses released on May 17 1952, of which this lens was the first one. The presence of the "1Q" and a red T on the front indicates that the lens was produced for export, which is also indicated by the distance scale (in feet).

Aperture range: f/3.5-f/22
Minimum focussing distance: 2.5 feet
Aperture blades: 14

You can take a look at its gallery (with examples) on my website, or at my complete Gallerie de gear.

The dedicated ARG-file that I use for this lens: czjtessar50exa.txt

 -n
-XMP:Lens=Carl Zeiss Jena Tessar 50mm f/3.5 (EXA)
-XMP:SerialNumber=3692001
-EXIF:MaxApertureValue=3.5
-EXIF:FocalLength=50
-EXIF:FocalLengthIn35mmFormat=50
-EXIF:FNumber=3.5