Originally posted by Stavri It's an exacta mount preset Red (T) tessar, smaller than the M42 tessar closer in size to a Jupiter 3, or other small rangefinder lenses. It's a fun little lens, (due to my choppy conversion) it works as a close focus prime
, really fun lens to play around with.
Yes, it's tiny, and looks a bit weird on the K-1
Yours is practically the same version of the Tessar I converted. The back of the lens is also looking similar.
The Altix mount is the breech-lock version of the Exa mount. Mine can be focused to infinity without problems, while the Exa/Exakta mount conversion needs some work to adjust for infinity.
I have the little Tessar cause I acquired an Altix camera for its 50mm Trioplan, and it came with a second "normal".
I used it to practice with the conversion procedure before doing the (more valuable) Trioplan 2.9/50mm, which also looks very similar to your lens from a certain distance.
It's really incredible how good these > 100 years old designs can perform, even on high res digital sensors. The rather primitive single coating calls for proper lens shading, but bokeh (Trioplan) and sharpness (Tessar) are there. The pictures are either quite good, or very poor, depending on the kind of lighting.
Sometimes the results are really special, I love that vintage look!
Cheers
Paolo