eyedeebee Posted June 27, 2012 Share #1 Â Posted June 27, 2012 Advertisement (gone after registration) Can anyone please give me any pointers into identifying white marks that I have just noticed behind the glass on my Elmar 90/4. I haven't used the lens for a while, but I'm fairly certain they weren't there last Time I had the lens out. In certain light they look like paint flaked off the metal, in others it looks like some kind of growth (fungal?). The glass itself remains clear. Â Apols for the quality of the pic! Â 27 Jun 2012 19:41 | Flickr - Photo Sharing! Link to post Share on other sites More sharing options...
Advertisement Posted June 27, 2012 Posted June 27, 2012 Hi eyedeebee, Take a look here Help identifying white 'stuff'!. I'm sure you'll find what you were looking for!
Guest Ming Rider Posted June 27, 2012 Share #2 Â Posted June 27, 2012 Difficult to tell from the photo. Â Yes could be fungus, but as it appears to be round the edge on the alloy, it could be an electrolytic reaction caused by condensation. If so, this is something peculiar to alloy and difficult to stop. You get it on alloy wheels. Â Is there tiny flakes of paint inside the lens? Link to post Share on other sites More sharing options...
andyedward Posted June 27, 2012 Share #3 Â Posted June 27, 2012 It looks like the black anti-reflective coating has come adrift from the inside of the barrel, leaving the aluminium barrel exposed. Like Ming said, check for tiny specks of black piant inside. The aluminium barrel looks white because it has oxidised. Thats my guess. Link to post Share on other sites More sharing options...
eyedeebee Posted June 27, 2012 Author Share #4 Â Posted June 27, 2012 Thanks both, can't see any loose specs of paint inside. If it is the anti reflective paint flaking, what is the likely result? Link to post Share on other sites More sharing options...
andyedward Posted June 27, 2012 Share #5 Â Posted June 27, 2012 In strong lighting situations, the white areas where the anti-reflective paint is missing may reflect uneven, and therefore unwanted light onto your sensor/film, ruining your image Link to post Share on other sites More sharing options...
jaapv Posted June 27, 2012 Share #6 Â Posted June 27, 2012 Still, the image made me think of bacterial or fungal growth, but not of the glass-destroying variety. Time to give this lens in the hands of one of the recommended repair people, methinks. Link to post Share on other sites More sharing options...
Messsucherkamera Posted June 29, 2012 Share #7 Â Posted June 29, 2012 Advertisement (gone after registration) It looks like the black anti-reflective coating has come adrift from the inside of the barrel, leaving the aluminium barrel exposed. Like Ming said, check for tiny specks of black piant inside. The aluminium barrel looks white because it has oxidised. Thats my guess. Â That was my thought, too. Time to send it off to your nearest board certified Leica surgeon. Link to post Share on other sites More sharing options...
earleygallery Posted June 29, 2012 Share #8 Â Posted June 29, 2012 It does appear to be that the coating has deteriorated - I have a similar 'problem' on my Summars. Â I'm not sure what happens but there's no evidence of paint flecks in my lens either, and it's not caused any problems so far as images are concerned. Â My advice would be to live with it, as long as it doesn't affect your images. Link to post Share on other sites More sharing options...
gravastar Posted June 29, 2012 Share #9 Â Posted June 29, 2012 I've seen something similar on older lenses. Difficult to tell from the pictures but it could be that the antireflective paint/varnish on the ground edge of the lens element has flaked off in places. Depending on how the element is mounted the flakes may be trapped in the cavity between a retaining ring and the barrel and will never be seen. Â Bob. Link to post Share on other sites More sharing options...
bocaburger Posted June 29, 2012 Share #10  Posted June 29, 2012 I've seen something similar on older lenses. Difficult to tell from the pictures but it could be that the antireflective paint/varnish on the ground edge of the lens element has flaked off in places. Depending on how the element is mounted the flakes may be trapped in the cavity between a retaining ring and the barrel and will never be seen. Bob.  Bingo! Give that man a cigar. Is this a new lens? I ask because typically that is seen with lenses that have been taken apart and put back together. Conscientious repairmen will always re-blacken the edges before re-assembly if any paint flakes off during the process. Link to post Share on other sites More sharing options...
TomB_tx Posted June 29, 2012 Share #11 Â Posted June 29, 2012 Agreed - paint on the edges of the elements. It probably hasn't flaked off - just "bubbled' in place and lost contact with the glass, which gives this appearance. My Zunow 50 f1.1 from ~1954 had this problem (along with a jammed helicoid), and is being restored by Gus Lazzari. Link to post Share on other sites More sharing options...
pico Posted June 29, 2012 Share #12 Â Posted June 29, 2012 It is almost certainly "Schneideritis". Google it. Link to post Share on other sites More sharing options...
Guest Ming Rider Posted June 29, 2012 Share #13 Â Posted June 29, 2012 It is almost certainly "Schneideritis". Google it. Â Interesting. A sort of Smegma of the lens Link to post Share on other sites More sharing options...
bocaburger Posted June 29, 2012 Share #14  Posted June 29, 2012 Interesting. A sort of Smegma of the lens  No, that only affects lenses with telescoping hoods. Link to post Share on other sites More sharing options...
Guest Ming Rider Posted June 29, 2012 Share #15 Â Posted June 29, 2012 Oh I see, ones with retractable covers? Link to post Share on other sites More sharing options...
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