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11-21-2014, 03:36 PM   #16
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Called the guy at KEH, He didn't seem to happy about the exchange as he asked whether the marks affect image quality, and it is too early for me to say whether it will because I have hardly used it.. So I just told him that its not something I have on any other lens. I also added that the marks were more in accordance to a BGN or UG Lens and not an EX one. Either way I emailed him a picture of the mark, but there was not much response..

Isn't there something about KEH return policy that sometimes you might have trouble returning if you have a bad return history or something like that..

11-21-2014, 04:07 PM   #17
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QuoteOriginally posted by dcshooter Quote
Gotta disagree with Mark here. Not worth a return in my opinion.

If you can only see it when shining a strong flashlight through it and not when holding it up to the light, then it is honestly not an issue, since it's not going to affect sharpness or contrast to any perceptible degree. It takes a lot more than you would think for that to happen, and certainly not something as minor as this. The flashlight test will tell you a lot of truths about the condition a lens is, but it will tell you a lot of lies about how serious any problem you see is, too. Just look at all that dust (actually not a bad level at all).

Probably dried cleaning fluid, as some others have said. If it were dried oil or plasticizers, you would see a perceptible haziness to the lens when holding it up in front of a window, etc. Even brand new lenses will have internal cleaning fluid marks if you look closely enough. Dust too. All of your other lenses probably already have as bad or worse on their front and back surfaces while you are shooting with them, even after giving them a microfiber wipe or a hit with a lens pen, which both will leave similar residue. And you'll see the same if you look hard enough even on a brand new return from a CLA.

I'm not sure this one has actually been opened, since I don't see any obvious marks on the rear mount screws, and most DA lenses have to have at least part of the rear mount removed in order to remove the rear group for cleaning. Of course, I might be missing something, as the photos are rather low res.

Looking at the pics you linked to form the firs tlens you sent, I'm not sure that's fungus, either, although it's hard to tell with the angle. If the mark was on the actual size of the lens, rather than the front or back surface, it looks like it's just that some of the blacking on the ground glass side of the lens group had chipped off. Probably wouldn't have affected anything. If it was on a "surface" of the lens, then it looks more like cement separationthan fungus. Now that would have been a problem. Spilled milk at this point, I guess.
Excellent point dcshooter. I guess I was engaging my OCD mindset I don't like seeing any marks and as such the psychology for me is a lens with marks means it is not any good. Perhaps I am a little to sensitive to grime

It always comes down to sharpness. I looked at the tests and it does seem like the lens is a little soft at f16 and f22 (a macro lens of this type should have almost no diffraction IQ loss). But to be true I can't be sure if the softness is expected or not.

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