I know that the Tele-Rolleis are highly prone to lens separation. Accordingly, examples that don't have separation command significant premiums. What are the effects of separation, and short of disassembly and re-cementing the lens, what is the treatment for the symptoms? Is using a lens hood sufficient? How bad does it have to be before considering re-cementing the lens? Any thoughts on the issue are greatly appreciated.
I know that the Tele-Rolleis are highly prone to lens separation. Accordingly, examples that don't have separation command significant premiums. What are the effects of separation, and short of disassembly and re-cementing the lens, what is the treatment for the symptoms? Is using a lens hood sufficient? How bad does it have to be before considering re-cementing the lens? Any thoughts on the issue are greatly appreciated.
I had a 50 summicron that had separation around the edges of the front element. I bought some of the flat black paint used to paint the interiors of film chambers and painted over the bad areas on the lens that were separated; these were only two spots that intruded about 1/8" to 3/16" circumferentially. My f2 lens was now (rough estimate) a f2.3 lens. I never could see any difference in the quality of my prints/negs and used the lens for almost an additional 10 years. I can't recall what finally happened to it.
From 2.8 to 16 I am sure it was completely out of the image frame. However, if the separation is in the middle (unlikely) you won't be able to salvage the lens; it will have to be heated, separated, cleaned and re-cemented.
Certainly was ugly looking at the front element but did not appear to be of any major consequence.
I had never problem with separation on my Tele-Rolleiflex but I did have problem with separation with not one, but TWO Rolleiflexes Planar 2.8. I had them both re-cemented by a very skilled optician and my impressions are mixed: one was ok - looking at pictures you couldn´t tell the lens one day had a separation - but the other never again achieved a good result and the camera was disassembled for parts.
From my experience, it´s a lottery (is there this expression in english?) where you may win or loose.
Now I purchased a Voigtländer Bessa II with Heliar lens almost entirely separated and I took a few pictures with it before disassemble the lens but I didn´t have them developed yet to see what effects the separation causes.
I do think that lens separation is progressive. I had all around separation in a 135 rodagon that slowly increased over about 15 years. When I stopped using it I still really couldn't see the affect on my printing but it was about half way from the edge to the center.
What would I see in a negative that would indicate separation was causing a problem? Would I have reduced contrast, some kind of distortion, really bad lens flare from light sources in the frame?
What would I see in a negative that would indicate separation was causing a problem? Would I have reduced contrast, some kind of distortion, really bad lens flare from light sources in the frame?
As far as I know the separation causes a "softness" like old style meniscus lenses. Again, I don´t have my films developed yet to say if for sure, so this is what my friends told me. But as soon as possible I will reply with some images.
As far as I know the separation causes a "softness" like old style meniscus lenses. Again, I don´t have my films developed yet to say if for sure, so this is what my friends told me. But as soon as possible I will reply with some images.
Like scratches it depends entirely on the extent. I have a Summitar I bought years ago for only $125 with some edge separation. I have seen little evidence of this in my photos vs my Summicron or Summarit and the separation has not continued to expand best I can see.