Collapsible Summicron 50mm f2. Leica screw mount. Leitz product code SOOIC. Serial number in the 1.35 million range, manufactured in 1956. Meter scale on the focusing helicoid.
A classic fast standard lens from Leitz. Following the Summar and Summitar, it appeared as the third-generation high-speed standard lens. Its overwhelming resolving power caused quite a stir in the photographic industry at the time, and together with the later debut of the Leica M3, it became one of the key lenses that defined Leitz’s golden era.
Although the collapsible Summicron was produced in relatively large numbers, many examples today suffer from cleaning marks or deterioration of the middle element, and lenses that truly deliver their original performance are becoming increasingly scarce.
This particular lens has been thoroughly serviced, offers excellent image quality, and is a well-sorted, ready-to-use example.

There are some light signs of use such as minor scuffs on the front of the barrel and the collapsible section, but no noticeable damage. Overall, the exterior condition is fairly good.
Fully overhauled in January 2026. Thanks to careful servicing, both the aperture ring and helicoid operate very smoothly. Rangefinder coupling is spot on and focusing is accurate.
The glass shows slight coating deterioration, along with very shallow cleaning marks on the middle and rear elements, but no impact was observed in actual shooting tests. Performance remains very good, including in backlit situations. A collapsible Summicron well suited for regular, hands-on use.