View Full Version : I'm probably over reacting (Re: 90mm lens)

Tom N
14-Feb-2006, 18:50

I know I'm probably over reacting and being paranoid but I have a question regarding a 90mm f/8 Super Angulon lens that I just got.
If I unscrew the front lens element from the shutter, looking at the rear of the front element (the shutter side) at certain angles to the light I can see 4 or 5 white spots in the center and a blueish smudge near the edge. The smudge was much bigger but I cleaned it as well as I could and it's now much smaller. Now the blueish smudge near the edge doesn't bother me because when I stop the lens down that part of the glass will be behind the aperture blades anyway. It's the small white smudges in the center that I'm concerned about. I'm pretty sure they are in/on the lens coating so I'm wondering if there is a way to polish them out or something. Or maybe it's nothing to worry about.


Jack Flesher
14-Feb-2006, 20:46
Hmmm... If the "white spots" look kind of like snowflakes it might be fungus -- and if it is and doesn't clean off, you are pretty much screwed.

Tom N
15-Feb-2006, 08:07
Well the white spots are pretty small but I looked at them with my loupe and they look like they have a soft feathered edge. Not sure if they look like snowflakes but maybe. Kind of reminds me of mold on a piece of bread. Not good.

I'm thinking about sending the lens back for a refund less the shipping cost. So I'll be out at least $80. I'm not too happy right now.

Leonard Evens
15-Feb-2006, 08:36
You should try the lens and see how it performs. If you want to be specially careful, do systematic tests. Use an appropriate target and try to estimate lp/mm at the center and edges for selected apertures you expect to use during shooting. Also, check overall contrast. The latter is important because the most likely effect of the sorts of things you describe is increased flare which will decrease contrast. If the lens is adequate for your needs, don't worry about what you see on the lens. It may be possible to clean the lens better than what you have done, but that should be left to experts, such as the Grimes people. If the lens is old, I would be more concerned about shutter accuracy myself, and I would send it for a clean and adjust in any case.

Andre Noble
15-Feb-2006, 08:55
"If the "white spots" look kind of like snowflakes" - as in white? Or as in Having a crystaline, repetetive type structure.

He already said they were white and small - that in itself, if not explained further qualifies as "looking like snowflakes"

15-Feb-2006, 09:31
I had this problem too, a camera technician told me the spots were the beginning of mould or fungus which eats into the grass if not caught in its early stages. He told me it's possible to clean the lens, but the spawns are there and in time it'll come back. After this I has visions of the lens infection all me others so I quickly got rid of it.

15-Feb-2006, 10:35
"If the lens is adequate for your needs, don't worry about what you see on the lens".
??? How come? And if the mold is alive and it continues to eat the lens surface and to make a bigger spot..?

Jim Rhoades
15-Feb-2006, 12:35
I had a lens fungus problem once. Mine looked like spider webs made by a drunk spider. I'm with C.Alex and GPS on this one. It will come back, it will grow more. If it was Schneideritis, dust, or cleaning marks I'd say test the lens and be happy. I have a f/2, 50mm Nikkor with a chip in the coating. It's been there for 30 years. No Problem, never know it. But... Accept no lens with any hint of fungus.

Tom N
15-Feb-2006, 16:17
So I contacted the dealer, explained the situation and they offered to take the lens back and even pay for all of my shipping charges. Very nice of them. So back she goes!

Thank you all for your responses.

Donald Qualls
15-Feb-2006, 20:41
That's a dealer deserving of some recognition, IMO, especially if it's a seller on that auction site...