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John NYC
13-Jan-2012, 15:13
I'm looking at a lens and there are some small spots around the perimeter of one of the inner rear elements where the glass meets the place where it is set in place. They don't look like fungus. They are a milky clear color if there is any color at all. Is this just aging of the glue/cement? How common is this? I have seen it in several lenses (I don't have the lens I am talking about right now, so I can't show you a picture).

johnielvis
13-Jan-2012, 16:09
you mean "schneideritis"? are they bubbles-looking?

John NYC
13-Jan-2012, 17:54
Yes, but they are slightly larger than what I have seen people call Schneideritis. I'd say they are about 1-2.5mm wide.

Gem Singer
13-Jan-2012, 18:14
Sounds like the beginning of lens separation. Can't say for sure without seeing the lens.

johnielvis
13-Jan-2012, 19:04
I got em on a couple....they don't seem to be doing anything bad...except maybe causing some flare that I haven't noticed yet---the ones I got are not visible to the light rays that travel through the lens...so I guess it's benign signs of old age.....

maybe "age spots"....

E. von Hoegh
14-Jan-2012, 08:17
Schneideritis.

Dan95
14-Jan-2012, 08:20
Schneideritis.

What are the effects of schneideritis ? :confused:

E. von Hoegh
14-Jan-2012, 08:26
What are the effects of schneideritis ? :confused:

Reduced resale value.

John NYC
14-Jan-2012, 12:23
I thought Schneideritis was tiny little spots on the paint inside the lens. These spots are more where the glass is cemented in place. Perhaps there are variants of Schneideritis that are this instead.

Thanks for the help folks.

ic-racer
14-Jan-2012, 14:47
Most of the separated lenses I have dealt with have more of a crescent shape irregularity. Sometimes things like you describe wipe right off. But sometimes they don't :(

I usually check so see if light passes through the abnormal area at f22. If not then I don't worry. If light passes through that area at f22 at any part of the image circle, I'd go after it and give it a shot to see if it will wipe off.

John NYC
14-Jan-2012, 15:02
Most of the separated lenses I have dealt with have more of a crescent shape irregularity. Sometimes things like you describe wipe right off. But sometimes they don't :(

I usually check so see if light passes through the abnormal area at f22. If not then I don't worry. If light passes through that area at f22 at any part of the image circle, I'd go after it and give it a shot to see if it will wipe off.

I don't think it would affect the image even wide open. It is literally only where the inner elements meet the side of the barrel. It is inside so can't wipe it off.

E. von Hoegh
17-Jan-2012, 07:42
I don't think it would affect the image even wide open. It is literally only where the inner elements meet the side of the barrel. It is inside so can't wipe it off.

That is Schneideritis. The glass is not cemented to the barrel; there is a coat of black paint on the ground edges of the elements. For whatever reason, the black paint sometimes bubbles up off the glass and causes these spots. Separation often results in mirror like or colored reflections.

John NYC
17-Jan-2012, 08:48
That is Schneideritis. The glass is not cemented to the barrel; there is a coat of black paint on the ground edges of the elements. For whatever reason, the black paint sometimes bubbles up off the glass and causes these spots. Separation often results in mirror like or colored reflections.

Very helpful, thanks.