Summicron 50mm f2, first generation. This example is the early fixed-mount type. Serial number is in the 1.4 million range from 1956. It belongs to the very first production lot of the fixed-mount version, falling within 1400001 to 1402000. The immediately preceding lot was the collapsible Summicron.
The product code is SOSIC-MS, later 11818. Distance scale is in meters, with a minimum focusing distance of 1 m. It uses a modified Gauss design with 6 groups and 7 elements. The optical formula was developed with an emphasis on contrast, yielding excellent resolution and making this lens widely regarded as one of the classics.
The Summicron series remains in production today, but the first generation, with its beautifully finished chrome and elegant form, enjoys enduring popularity. The chrome finish around the front rim of this example is relatively shiny, carrying a hint of the aesthetic seen in the earlier collapsible Summicron.
A quintessential old lens that is both delightful to admire and rewarding to use. It pairs wonderfully not only with M-mount bodies but also with modern mirrorless cameras.
Filter size is E39. Compatible hoods are ITDOO and IROOA.

There is a small amount of rubbing around the aperture ring, but the silver paint on the helicoid section, which tends to wear off easily, remains well preserved, making this a very clean example for an early first-type rigid barrel.
It received a full overhaul in November 2025. Thanks to the careful servicing, both the aperture and the helicoid operate smoothly. The internal anti-reflection lacquer has also been neatly reapplied, allowing for a tighter and more controlled rendering. Rangefinder coupling is spot on and focusing accuracy is excellent.
The glass shows a tiny spot of coating deterioration on the rear element and a very slight cleaning mark on an inner element, but these have virtually no impact on actual shooting. The coating remains intact across all surfaces. Test shots produced very good results.
Period-correct genuine front and rear caps are included.