PDA

View Full Version : White dots around the edges ("Schneideritis")?



Mika
19-Sep-2005, 02:22
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
19-Sep-2005, 04:50
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
19-Sep-2005, 05:02
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
19-Sep-2005, 05:40
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
19-Sep-2005, 07:06
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
19-Sep-2005, 08:16
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
19-Sep-2005, 08:52
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
19-Sep-2005, 09:15
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
19-Sep-2005, 09:39
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
19-Sep-2005, 10:23
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

Kerry L. Thalmann
19-Sep-2005, 11:22
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.

Exactly! I collected coins as a kid. So, to me MINT means just that - like it was just minted with absolutely no signs that it's ever been handled, let alone used, let alone imperfect in any way cosmeic or functional. For this reason, I almost never use the term MINT when describing something I'm selling. At the very least, to be MINT in my mind, a lens should be just like it was when it left the factory - in the box with the orignal caps and paperwork. Anything less than that and it becomes MINT- in my book. I still get a chuckle everytime I see someone describe a used lens as Mint+. I always picture getting a box filled with sand and bauxite to make my own lens.

That said, the lens Mika purchased is definitely not even close to MINT condition - even by the more relaxed standards typical on eBay. Think about it, if you bought a new lens and it was similarly inflicted with a case of Schneideritis, you'd send it back for a refund without hesitation - and rightly so. I also think $750 is way too much for a 31 year old single coated Symmar-S - even if it was in MINT condition (which it is not). If you check recently completed auctions on eBay, you will see several examples of much newer, multicoated 360mm lenses - without a hint of Schneideritis - selling for less money.

On the issue of Schneideritis, as others have mentioned it is caused by a delamination of the blackening compound around the perimiter of the of the lens elements. I have absolutley no documentable proof that it affects image quality or lens performance in any way. That said, my inuition tells me that if it's bad enough, it might reduce contrast slightly and perhaps make the lens a tiny bit more susceptible to flare. Think about it. The lens manufacturers blacken the edges of their lenses for a reason. If the blackening compound provided absolutely no benefit at all, why would they bother with the time and expense of applying it? I've got lenses dating from the 1920s through the present, and they ALL have this blackeing compound on the edges of the glass. So, it must be there for a reason - and my best guess at that reason is to minimize the chance of internal reflections. I'm sure a few tiny white "bubbles" in the blackening will have no observable affect, but when the surface area of the bubbles exceeds that which remains blackened, I begin to wonder. The only way to know for sure would be a controlled test using samples of the same lens type - one with significant delamination and one with none. I suspect any difference would be subtle (slightly reduced contrast), but I'd be surprised if there was no affect at all on a lens with severe Schneideritis. I'm not saying this would make the lens unusable and incapable of making excellent images, just that it would not be performing at it's absolute best.

At the very least, Schneideritis does impact resale value of the lens. As the condition of the lens was misrepresented, I'd return it to the seller for a refund. As long as eBay sellers are allowed to pass off imperfect merchandise as MINT, they will continue to do so.

Kerry

John_4185
19-Sep-2005, 11:56
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.

My clever wife has threatened to put up an auction: "Mint mints in mint mint box".

Just for hits.

Mika
21-Sep-2005, 05:43
Epilogue

Although John’s wife already had the appropriate last words in this matter, I thought I should give you the end of the story.

I approached the seller (on eBay) about the problem and suggested a partial refund of the price I paid. I think that he truly had not realised that the white dot phenomenon was an ”affliction” and not an original feature. He was a good sport about it and gave 160 USD off the price. It’s human to make misstakes, so I ended up giving him positive feedback, after all.

By the way, I talked to a saleswoman on Teamwork who had the experience that all lenses of this age and type have the white dots. Some have more of it, some less. In other words, Symmar’s and Symmar-S’s all have it as well as earlier Symmar-S MC’s. She was adamant in her opinion that these dots do not affect picture quality. But, the credibility of a seller is less than the testimony of a user (althoug no-one has yet testified to the end that the dots have any practical significance, apart from the value of the lens).

All in all, for full- and 2/3-body portraits, a dot here or there doesn’t matter (especially not if they are Polaroids). For my next lens, which will be 150, 165 or 210 mm for 4"x 10" panoramas, I will seriously consider buying a new one … or at least ask a lot of questions before buying a used one.