Archived posting to the Leica Users Group, 2004/11/21
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]eric wrote: >I just bought a summaron 35mm 2.8 - was advertised as 'bargain' condition. > >There is an irregular very thin rim of blackening around the periphery of >one ofthe rearward elements. >I have never seen this before on a lens. > >Anyone know what could cause this? >Fungus? Coating pulling off an element? > >Eric >_______________________________________________ >Leica Users Group. >See http://leica-users.org/mailman/listinfo/lug for more information > > > Eric- I had a lens with a similar 'dark' line around the edge- a vintage lens cemented with the balsam and I had John Van Stelten tend to it. In my case the problem was the balsam cement was old, and separating. He heat trated the elements to separate them completely, cleaned and recemented with a modern optical adhesive that is not supposd to deteriorate like that (but who knows what 50 years will bring!). Now this was on an old Rollei, but once he finish recementing and I had the lens recoated (He does the old single layer doatings, so it was 'authentic!) the lens was wonderful. I also have a Summaron, though I got a real jewel and only needed DAG to do a CLA, but it is a very servicable lens, and since it is a very compact lens, I even used it with an adapter on my M7 on occasion. Cettainly not a Sumilux aspheric, but it'll hold its own with a lot of newer glass. Have fun! Dan