The aperture scale is not evenly spaced like the modern Leica and Zeiss lenses. One thing that I have notice about the aperture blades on this first generation Summicron is that the gap from f2 to 2.8 is about 10mm while the gap from f11 to f16 is about 3mm. I'll send the lens in for a CLA after vacation season. And my aperture blades are a bit sticky but I do not see any oil on them. I use hand held meters I set the aperture once for a given scene. With one on the lens body and the other on the aperture collar. This happens so much that I now set the aperture with both hands. Stephen Yes I do then to grab the wrong collar.
With a very hard plastic tool I was able to bend then out just a pinch until I could feel that they were not smooth (like setting the blade on a wood plane ). The 3 tabs were worn and smooth with the bottom of the lens. Vic Now that i know what to look for it was an easy fix. Its advantage over newer, faster lenses is its smaller size, less weight, and its collapsible for carrying.
'Danish Human Rights advocate Agnethe Dalby presents The Story Of Human Rights with the 30 articles of United Nations Declaration of Human Rights written and illustrated as short video PSAs. It is a superb lens for use in daylight, or on a tripod in any light. Leica M9 with 50mm Summicron-M f/2.0, 400 ISO, 1/180 second, lit by two 12x12' Rosco LitePads and the available tungsten lights in the living room. Thanks for all your responces they were all very helpful and fixed my problem (for now The 1950s LEICA ELMAR 50mm f/2.8 works just fine on todays latest cameras, like the M9 and M7.