Quote Originally Posted by Hawkeye View Post
Im looking for a summicron or elmar 50mm for my M2.

Id prefer to stay away from lenses that may have fogging issues. Im assuming at some point in time the fogging issue was resolved. True?

If true, what serial number (date) should I look for to avoid lenses that may have, or might get, lens fog.

Thanks,

Mark
Any lens may develop internal fog if stored in poor (damp) conditions. I own all the iterations of the 50mm Summicron M and cannot say that any one has a greater tendency to fog (apart from greater age). The position with Elmars is different - this is a Tessar-type (4-element) lens, Leica chose to place the iris diaphragm right behind the first element instead of between elements 2 and 3, this lens, especially in the f2.8 version, is notorious for fogging due to evaporation of oil from the iris. I have scrapped two examples over the years because of this, the very latest version may be better (no experience of this).