Summaron 35mm f2.8. This is the somewhat less common Leica screw mount version. The serial number is in the 1,620,000 range. Although M-mount Leicas had already become the mainstream by this time, the IIIg was still in production, and this lens was made in 1958.
The Leitz code is SIMOO / 11006. Made in Germany. The filter size is E39.
The new Summaron, half a stop faster than the previous f3.5 model, uses new optical glass and features a 6-element, 4-group double-Gauss design.
It shares its barrel design with the 8-element Summicron, giving it a very stylish appearance. Mounted on a Barnack Leica such as the IIIf or IIIg, it looks absolutely superb.
At full aperture, the rendering is generally gentle, yet center resolution is quite good, and the dramatic peripheral fall-off gives the images plenty of character. This is something of a hidden favorite lens, with some users even preferring it to the 8-element Summicron.
Compatible hoods include the ITDOO, IROOA, and others.

There is very slight rubbing on the front edge of the barrel, but no noticeable scratches or dents, and the overall appearance is very clean.
The lens was overhauled by the previous owner last year, but just to be safe, we had it fully overhauled again in May 2026. The aperture ring has a pleasantly positive click feel, and the helicoid now operates smoothly with a nicely damped touch. The infinity lock also settles into place very nicely. Rangefinder coupling and focus accuracy are both excellent.
The glass has 2 to 3 very fine cleaning marks on the front element, along with slight coating wear, but neither should have any noticeable effect on image quality. For a Summaron 35mm f2.8, a lens type known for haze, the glass is quite clean. The results of our test shots were also very good.
Comes with a period-correct original front cap and a plastic case.