White dots around the edges ("Schneideritis")?

[Mika]

I just bought a used Schneider-Kreuznach Symmar-S 6,8/360 – a beautiful lens! But, alas, it has a problem touched upon in a few other threads. However, I didn't find a satisfying answer by a search through these threads.

The problem is white dots. Not fungus, not dust, but hundreds of small dots in different sizes around the edges of the lens. They fill the whole area between glass and barrel (maybe 5 mm wide and all around) and the phenomenon is both on the front and rear element.

In an earlier thread, it was suggested that this was paint flaking off but, no, this is different: it looks more like a starry heaven, with hundreds of small dots. It cannot be paint flaking off, since there are no paint-flakes in the lens, right? It seems deliberate, actually, not something that would have happened over time … Exept from this everything is clear and nice (the glass is clear etc.).

In another thread it was stated that this is harmless, although someone called it "Schneideritis", which sounds like an illness, which usually is a bad thing …

If anyone has any more insight into this, please let me know!

[Don Sparks]

I have a Schneider 210mm and a Fujinon 90mm with the Schneideritis. It dosen't effect picture quality but it might hurt the resale of the lens.

[Simon Knight]

It is Schneideritis. If you don't see any flecks of paint batween the elements you don't have a problem. A large proportion of Symmar-S lenses I have seen have this problem - it won't affect performance.

If you want to get it fixed, Schneider Optics will disassamble the lens and repaint it.

[Joseph O'Neil]

Yep, I have the same thing here. Schneider 180mm Componon lens I had mounted in a shutter (Compur, #1 I think) . Becasue of the "white dots" I picked it up dirt cheap.

Works great on all counts. No affect on picture quality at all. In fact, because the "white dot syndrome " (does that sound better than "Schneideritis" ? , does seem to lower resale prices, i kinda keep my eyes open for this sort of thing at flea markets, swap tables, used sales, etc.

Go ahead and enjoy your lens.

joe

[ronald moravec]

Got it in a 35mm shift lens for a Leica. Came that way and has not changed for 20 years. Pictures are fine.

[neil poulsen]

People are obviously getting good photographs from lenses with this affliction. I know that I have.

But I wonder about whether or not they affect the quality of the photograph. Aside from just being white dots, that's white light flying around inside your lens. We know that glass to glass or air to glass surfaces reflect some quantity of light. I think it's glib for Schneider to suggest that the negative remains unaffected and suspect those dots contribute some amount of flare.

[John Layton]

OK - but just what are these white dots? I'm guessing they might be "blooms" of oxidized aluminum - perhaps induced by some inappropriate plating or other finishing. Does anyone know the answer? Bob Solomon - Kerry Thalmann - et. al - can any of you comment on this?

[Melchi M. Michel]

John,

The black paint that coats the edges of the lens elements (actually it is a more waxy material than paint), generally does not flake off, but merely bubbles off, pulling away from the element surface. I have taken a couple of old Symmars apart to clean of haze on the internal surfaces, and I can assure you that these white dots are only the result of this bubbling off. Thus, these dots are "white" only in the same sense that ground glass is white, and for the same reason. The edges of the lens elements are ground and when they lose contact with the paint surface, they appear white. I found no oxidation of any kind inside these lens barrels, but even if there were some oxidation, chances are you would not see it because the paint is usually still attached (this explains why you don't find paint flakes on the internal surfaces).

[Mika]

Thank you all for your friendly replies – this is indeed a wonderful forum! It seems to me that Melchi has given the correct answer to the interesting question about the nature of the dots, thank you!

Even though this white dot phenomenon does not effect picture quality, or at least very little, I find it incorrect to put up an affected lens as "mint". If you take a look at the auction (the pictures are still visible, I think) at eBay, number 7544461634, you'll see what I mean (yes, this is the lens I bought). Now that I am aware of the phenomenon, I think I can actually see the white dots even on these low-resolution pictures …

I am putting together my first large format equipment and sadly few stores sell what I need, so eBay has been a necessity for some items. Usually I don't buy things I cannot inspect first and usually I buy new, but in large format the prices are astronomical for new gear and, after all, this is just a hobby for me …

[Dan Ingram]

There's nothing wrong with Ebay that a little careful research won't cure. I have two Schneider enlarger lenses with Schneideritis and they're great. However, a lens in this condition is not MINT. If there's one thing about the auction site that bothers me, it's the weird definitions of condition. I've had people tell me they consider MINT (or the hated "minty") to mean "perfectly functional" or "no serious defects." MINT comes from the world of numismatics, and refers to coins as they appear before they are circulated, with NO use or wear and in factory-perfect condition. Sadly, language is malleable, and in the post-modern era words mean only what the user wants them to mean. Anyhow, if it bothers you I'd contact the seller and talk about it -- but aside from the Schneideritis it looks like an awfully nice lens!

Dan