Archived posting to the Leica Users Group, 2001/05/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 10:53 AM 5/10/2001 -0700, Mark Bohrer wrote: >John: >All I know is that my 1954-vintage 50mm F1.5 Summarit ended up with a very >scratched front element after repeated cleanings with lens tissue over many >years of use (1969-1975). It was pristine when I found it in my parents >basement. If I'd bought and used an E41 UV filter, it would have stayed >pristine. No, it would not have "stayed pristine", Mark. Leitz was barred in 1954 from using the vacuum-coating technologies controlled by Zeiss (though Voigtländer and Schneider did have access to the process). Hence, Leitz was forced to use the older 'drip-coating' method, which left a very moist coat. Over time, this dries out and leaves a powdery residue which can be easily rubbed off. If your lens had been given a proper T-coating, of course, the coating would have been MUCH harder. (I have some Prewar and Wartime Zeiss lenses which still have "pristine" coatings despite never having been routinely covered with a filter of any sort.) Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!