Rear Lens Element -- Mark/Scratch? What is this?


New member
M43 Voigtlander Nokton 25mm rear lens element has this odd mark on it. Any idea what it is, and if it is likely to cause any problems?


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I guess testing it out would be the only real answer to your question. I came across this article a while back, and it may be of interest. I also remember a demo in the '60s where Zeiss engraved their name on the front element of a lens and then shot a series of stills with it, and it was surprising how much glass impairment you could get away with.

Chris Young
It looks like either a scratch or a deposit of some sort. You might try cleaning it. My usual solvent series is water, ethanol, acetone. Loupe it first to see if there is physical damage. Not much you can do if it’s a scratch other than see if the manufacturer can replace that element.
Was this an ebay purchase? I've had so many bad experiences my default assumption has become there is something wrong the only question is can I live with it? If you can't see the defect in the final image then leave it alone. In this case looks like a scratch in the coating but because it's on the edge it might be outside of the sensor coverage.
What methods have you tried to remove it? I'd be surprised if some lens fluid and lens paper wouldn't buff it right out.

It's not my lens but I think you're right about removing the mark. I was just derailing the thread with a Seinfeld reference (sorry filmguy :().