Collapsible barrel Summicron 50mm f2, Leica screw mount. Serial number in the 1.7 million range, manufactured in 1959.
A few years after the launch of the Leica M3 in 1954, only 1,160 units of this L-mount version were produced during the era when the M series had already become mainstream. Leitz product code: SOSTA / 11018. Focusing scale is in feet, with a minimum focusing distance of 1 meter. Filter size is E39. Compatible hoods include ITDOO, IROOA, and 12585.
This lens was produced during the golden postwar era of Leitz, alongside iconic releases like the M2 button rewind and early batches of the M3 Black Paint. It boasts high precision and a beautifully refined finish.
When mounted on a Leica IIIf or contemporary IIIg, it looks exceptionally stylish—adding to the bold presence of any Barnack Leica.
A rare gem.

There is a pinpoint-sized dent on the knurling of the helicoid, and light scuff marks can be seen in various places. The overall appearance shows some signs of use.
Fully overhauled in June 2025. Thanks to careful servicing, the aperture clicks firmly, the helicoid operates smoothly, and the overall handling is very pleasant. The internal matte black coating has also been reapplied to reduce internal reflections, promising tighter and more contrasty rendering. Rangefinder coupling and focusing accuracy are both excellent.
The inner elements show a few faint cleaning marks, and part of the coating has slightly deteriorated, giving a faint hazy appearance, but this should have no noticeable impact on actual image results. The front element is clean and free of cleaning marks. Shooting tests also yielded excellent results.
A well-used but solid Summicron 50mm f2 1st version with collapsible barrel in Leica screw mount.
Comes with original front cap and plastic case.