I purchased a Summicron 1:2/90 about 30 years ago. It is in excellent condition, having been used probably no more than a dozen times, if that many. It has been housed in its original box, free from moisture and sunlight for 99.9% of its lifetime. Upon close inspection of the lens, I notice that the diaphragm blades have a splotchy appearance (wet-like). Is this a normal thing, or do I have a problem? Any help will be appreciated. Thank you.

-- Max Wall (mtwall@earthlink.net), May 27, 2001

Answers

Sounds like a bit of oil is seeping out on the diaphram blades. This isn't too common with Leica lenses, and sometimes occurs when the lenses are subjected to high temperatures. It isn't much of a problem on a rangefinder lens with a manual aperture-its just not that pretty. It can be more trouble on an SLR lens, as the diaphram can become sticky and not open up/ close down correctly during and after exposures.

-- Andrew schank (aschank@flash.net), May 27, 2001.