@McLeica Posted March 5, 2013 Share #1  Posted March 5, 2013 Advertisement (gone after registration) Hi  I have an old 1955 Type IV 50mm Summicron that is in very good condition.  Both the barrel and front and rear elements are perfect, however on the inner elements there are these odd concentric circles in the middle. They look almost like perfect circular wear marks or perhaps a deterioration of some sort. They don't effect the lenses performance in any way though.  In all other ways a perfect 58 year old lens that I want to sell, but need to know what this issue is and how to fix it.  Picture attached and any advice would be greatly appreciated.  Thanks Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/199775-50mm-summicron-type-iv-rigid-problem/?do=findComment&comment=2261483'>More sharing options...
Advertisement Posted March 5, 2013 Posted March 5, 2013 Hi @McLeica, Take a look here 50mm Summicron Type IV Rigid Problem. I'm sure you'll find what you were looking for!
@McLeica Posted March 6, 2013 Author Share #2 Â Posted March 6, 2013 Ooops...sorry! That should be a 1957 Type II. Link to post Share on other sites More sharing options...
alfredian Posted March 6, 2013 Share #3 Â Posted March 6, 2013 A couple of thoughts here - Do the Rings appear at all light-angles? Not an internal reflection of the lens barrel interior itself? Visible by reflected light, from the rear only? What happens when viewing a light from the far end (front-to-back or vice-versa), especially a point-source, such as a distant lamp or the moon? Â Other than an odd internal-reflection of some sort, the only thing that comes to mind is that a pair of cemented elements are coming unstuck. Have you checked out a cutaway lens-diagram to look for where (how deep into the lens) any cemented ones are? Â Good news? I don't think a fungus would grow in this pattern. Best, alfredian Link to post Share on other sites More sharing options...
@McLeica Posted March 7, 2013 Author Share #4 Â Posted March 7, 2013 Hi Alfredian...no they don't appear at all angles. Looking straight through the lens they are invisible. I had to move the lens around to get the angle to take the photo of them. As I mention they don't appear in any test shots. Â I think you may be right on the cemented elements theory. Balsam splitting perhaps? Link to post Share on other sites More sharing options...
tobey bilek Posted March 8, 2013 Share #5 Â Posted March 8, 2013 Someone tried to clean the interior with a cloth. The coatings are soft as warm butter,much softer than the outside which are not hard coatings themselves. Link to post Share on other sites More sharing options...
tobey bilek Posted March 8, 2013 Share #6 Â Posted March 8, 2013 Someone tried to clean the interior with a cloth. The coatings are soft as warm butter,much softer than the outside which are not hard coatings themselves. Link to post Share on other sites More sharing options...
@McLeica Posted March 8, 2013 Author Share #7 Â Posted March 8, 2013 Advertisement (gone after registration) Maybe the simple answers are the right ones. Â Anyway, I have sent the lens in to be stripped down and examined by Graham Rose at Gres.co.uk for a proper diagnosis. Â Will post with the verdict!! Link to post Share on other sites More sharing options...
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