Archived posting to the Leica Users Group, 2000/06/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]I noticed that my 180mm f/3.4 Apo-Telyt-R was calling for about 1/2-1 stop more exposure than I was expecting under "sunny 16" conditions. In comparison with the 50mm Summicron on the same camera (R8), the 180 was indeed calling for about 1/2 stop more exposure. In daylight the 180 glass looks perfectly clear and unclouded, but when I peer through the lens front-to-rear against a darkened background and shine a flashlight across the rear element, then the rear element seems to light up with numerous tiny bright specks, like many stars against a night sky. (I haven't had the nerve to subject my other lenses to the same test.) There is no gross deterioration on picture quality, but I'm not confident I could tell if there was just a modest decrease. I'm sure I'm going to feel compelled to send the lens to Sherry for her inspection, but can any of you LUGGERs give me an opinion based on your own experience? I briefly entertained the notion that the difference in exposure readings was due to more elements in a telephoto, but I believe that was just wishful thinking. Thanks for any help..........Julian