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John Conway
18-Feb-2014, 05:29
Does Shneideritis get worse over time? Is it worth it to buy a lens that has the defect ?

Leigh
18-Feb-2014, 07:19
One would expect so, since it didn't leave the factory that way.

It appears to be a defect in the aluminum anodizing, but that's based solely on reports of others.

I do not buy any Schneider lenses due to the existence of Schneideritis, but that's a personal decision.

- Leigh

hoffner
18-Feb-2014, 07:40
Of course it's well worth to buy lenses with this "defect". It has no real effect on the picture you could discern.

Leigh
18-Feb-2014, 07:54
Of course it's well worth to buy lenses with this "defect". It has no real effect on the picture you could discern.
My concern is not the Schneideritis itself, which does not affect the photo.

If Schneider chooses to ignore a problem that has existed for decades, and is so common that it has a name...

What other defects do they choose to ignore that we're not aware of because they're less obvious?

- Leigh

John Conway
18-Feb-2014, 08:00
Whenever I inquire about a lens being sold with the defect it is always stated that there is no effect on image quality. But lenses are made with non reflective black inside for a reason . They don't make them with little silver dots in there for the same reason . Some of the lenses are offered at very good prices though .

Ari
18-Feb-2014, 08:04
I've never noticed any difference in image quality with a lens that has Schneider-itis; the only difference is the lower selling price.

Dan Fromm
18-Feb-2014, 08:09
Leigh, schneideritis isn't due to failed anodizing, it is due to poor adhesion of the black paint applied to elements' edges. In spite of the name, it occurs with other makers' lenses. For example, most of my Boyer lenses have bad cases. But not all, and there's a problem. It isn't clear what factors besides the edge blacking material -- surface treatment before application? glass type? relative humidity when the blacking was applied? ... -- make it happen

I'm inclined to think that "WE ARE RIGHT AND WE ARE NOT GOING TO CHANGE ANTHING! IF THERE IS A PROBLEM IT IS THE CUSTOMER'S!" is a disease that afflicts mainly German manufacturers. VW, BMW and E. Leitz and successors come to mind.

Lenses from a number of makers have problems with early synthetic adhesives -- Rodenstock and Voigtlaender, in particular -- too. These defects, like schneideritis, took years post-manufacture to manifest themselves, and not all lenses made with the "bad" adhesive develop them. Perhaps lens makers should try accelerated life testing before releasing lenses made with new materials even though I've never understood the chemistry behind it.

As a matter of practical interest, Leigh, which makes of LF lenses do you use?

hoffner
18-Feb-2014, 08:11
Whenever I inquire about a lens being sold with the defect it is always stated that there is no effect on image quality. But lenses are made with non reflective black inside for a reason . They don't make them with little silver dots in there for the same reason . Some of the lenses are offered at very good prices though .

If you understand lens optics find out what a percentage of light that hits the lens can bend so that it hits the partially blackened edge, leaves it, hits the other lens surface and reaches the film... The amount is simply not discernible on a picture.

Ari
18-Feb-2014, 08:16
I've also seen it on older Fuji lenses; Fuji-itis.

Leigh
18-Feb-2014, 08:23
As a matter of practical interest, Leigh, which makes of LF lenses do you use?
Hi Dan,

Back when I was shooting chromes, I learned that the best color fidelity across the lens set was achieved
by standardizing on one brand and lens series.

Although I only shoot B&W now, I still adhere to that principle.

My main lenses are ...
Rodenstock Apo-Sironar-S (all seven available FLs from 120/5.6 through 300/5.6), plus
Rodenstock Apo-Macro-Sironar-S 180/5.6,
Rodenstock Apo-Sironar-W 210/5.6.

Others are ...
Nikkor SW 65/4 and 75/4,
Fujinon SWD 90/5.6 (this is a marvelous lens),
Fujinon SW 105/8 (250mm IC; very hard to find a 105 that covers 4x5 with movements),
Nikkor W 240/5.6 and 360/6.5,
Nikkor M 300/9 and 450/9,

Goerz Gold Dot Dagor 8-1/4"/6.8 (a real one, made in Switzerland).

There may be a couple of others floating around, but those listed are the ones I use.

There are also Rodenstock Sironar-N 150/5.6 and 210/5.6 that I'm trying to sell.

- Leigh

Nathan Potter
18-Feb-2014, 10:01
Dan, it sounds like you are ascribing the "Schneideritis" effect to the paint on the edges of the glass elements. I see the effect as blisters in the paint on the blackened aluminum, inside barrel. So I don't get your connection to the element edges vs the inside of the barrel. When I pick at this blackened surface it appears to be paint that is baked enamel of some sort. Under a microscope I think I see a pinhole in the paint and within that a white spot that looks like aluminum oxide. But native Al2O3 grows to a few hundred angstrom units depth and then typically stops since it is impervious to air at that thickness.

These white spots are clearly thicker than a few hundred angstoms so appear to be some kind of corrosion chemistry possibly as a result of improper or sloppy surface treatment of the aluminum prior to painting. They vary in size so this is likely a dynamic corrosion process that is continuing over time and quite likely enhanced by local humidity.

Like others here I cannot ascribe any degradation in optical properties with the few lenses I have that show the phenomena but I do worry a bit about some of the spots becoming loose and shedding onto the lens elements.

Yes, Leigh has a good selection of lenses and if I was as wealthy as he I would follow suit. Not because I was afraid of Schneideritis but because those are stunning lenses. :)

Nate Potter, Austin TX.

Dan Fromm
18-Feb-2014, 10:36
Nathan, my Boyer lenses with severe boyeritis have brass barrels, not aluminum.

BrianShaw
18-Feb-2014, 10:48
... I'm inclined to think that "WE ARE RIGHT AND WE ARE NOT GOING TO CHANGE ANTHING! IF THERE IS A PROBLEM IT IS THE CUSTOMER'S!" is a disease that afflicts mainly German manufacturers. VW, BMW and E. Leitz and successors come to mind...

Add Mercedes to that list. (I could tell you a story or two about my transmission, and the engine failure that is likely but yet to happen).

hoffner
18-Feb-2014, 11:01
These white spots are clearly thicker than a few hundred angstoms so appear to be some kind of corrosion chemistry possibly as a result of improper or sloppy surface treatment of the aluminum prior to painting. They vary in size so this is likely a dynamic corrosion process that is continuing over time and quite likely enhanced by local humidity.


Nate Potter, Austin TX.

In my amateur opinion the detaching paint is probably a result of outgassing of the paint layer.

Jac@stafford.net
18-Feb-2014, 11:02
Dan Fromm:

I'm inclined to think that "WE ARE RIGHT AND WE ARE NOT GOING TO CHANGE ANTHING! IF THERE IS A PROBLEM IT IS THE CUSTOMER'S!" is a disease that afflicts mainly German manufacturers. VW, BMW and E. Leitz [...]

OMG! I have all of those! My BMW motorcycle needed new fork seals at 104,000 miles. My 1958 VW Bug (http://www.digoliardi.net/58bug.jpg) is still running. Leicas - all okay after almost fifty years. And the Linhofs, Super Ikontas.

Dan Fromm
18-Feb-2014, 11:45
OMG! I have all of those! My BMW motorcycle needed new fork seals at 104,000 miles. My 1958 VW Bug (http://www.digoliardi.net/58bug.jpg) is still running. Leicas - all okay after almost fifty years. And the Linhofs, Super Ikontas.
I take you don't have a Leica-badged Minolta SLR made in Portugal.

Jac@stafford.net
18-Feb-2014, 12:14
I take you don't have a Leica-badged Minolta SLR made in Portugal.

That is correct. For a laugh, see this (http://leicarumors.com/wp-content/uploads/2013/03/Leica-Camera-new-plant-in-Portugal.jpg).

John Conway
18-Feb-2014, 15:34
I can not argue with anyone who has used Schneider lenses with the paint defect and achieved good results . I'm convinced that A lens with a paint defect will perform just as well as one without the defect. My only problem , after reading the technical opinions here , is will the lens get worse over time. The lens I am considering is a 360 f6.8 (ebay#301094860030) that will cost me a little over 500.00 . A good price for what it is , but not exactly cheap either. Also , this lens seems to have a serious case of Schneideritis. It seems to be all over the place. I have never seen oxidation or paint flaking get better over time.

Leigh
18-Feb-2014, 17:39
I have never seen oxidation or paint flaking get better over time.
At some point in the dim future, all the paint or anodize will have disappeared, and it stops getting worse.

That is not the same as getting better.

- Leigh

brucetaylor
18-Feb-2014, 18:48
"The lens I am considering is a 360 f6.8 (ebay#301094860030) that will cost me a little over 500.00. A good price for what it is , but not exactly cheap either."

I disagree, it's cheap! Not so many years ago it would have cost something like $1500? In 20 year old dollars? So in 20 more years it might get worse? I don't worry about the Schneideritis (or Fuji-itis or Lomo-itis). I think the likelihood of it affecting a picture is pretty close to nil and I'm getting a bargain. Buy it and shoot some pictures!

Nathan Potter
18-Feb-2014, 20:23
Nathan, my Boyer lenses with severe boyeritis have brass barrels, not aluminum.

Dan, what does boyeritis look like from brass? I wouldn't think it would be whitish like "schneideritis". Of course you can't have "schneideritis" on a brass lens plus I've never heard of "boyeritis".

Has anyone ever had "rodenstockitis" of "fujiitis"?

Nate Potter, Austin TX.

Dan Fromm
18-Feb-2014, 20:26
Nathan, boyeritis looks exactly like schneideritis. It is the same thing. What's wrong is your theory that it is due to corroded aluminum barrels.

I'm sorry that you've never seen boyeritis. Have you ever seen a Boyer LF lens?

Leigh
18-Feb-2014, 21:45
Has anyone ever had "rodenstockitis" of "fujiitis"?
Yes for Fujinon, though not nearly as common as for Schneider lenses.

I've never heard of nor encountered a similar problem with Rodenstock lenses.

- Leigh

Leigh
18-Feb-2014, 21:46
Nathan, boyeritis looks exactly like schneideritis.
How can a cosmetic defect on a brass barrel look exactly like a cosmetic defect on an aluminum barrel?

Or are we talking solely about black&white photos of the defect?

- Leigh

Nathan Potter
18-Feb-2014, 22:42
Yes Leigh, I'm still trying to understand why the appearance would be the same when the base metals are entirely different. Unless the effect is solely from the paint or the anodic film if that is used. The oxides of copper are usually reddish to blackish. Of course the chemistry could be more complex than just an oxide.

But looking at the schneideritis under a microscope the tiny blooms appear to pop up from the base metal, although admittedly I can't be wholly certain of that. Just trying to understand the histology of the mess I have with one lens.

Maybe I'll be forced to do a microprobe analysis of a bloom using Auger, on my own dime. I think the lens will survive a high vacuum environment.

Nate Potter, Austin TX.

Leigh
19-Feb-2014, 00:04
Hi Nate,

I wonder if we're talking about the same problem.

The Schneider lenses I've seen with Schneideritis have bright patches of varying size, from quite small to much larger than a pin head.

- Leigh

hoffner
19-Feb-2014, 06:24
Yes Leigh, I'm still trying to understand why the appearance would be the same when the base metals are entirely different. Unless the effect is solely from the paint or the anodic film if that is used. The oxides of copper are usually reddish to blackish. Of course the chemistry could be more complex than just an oxide.

But looking at the schneideritis under a microscope the tiny blooms appear to pop up from the base metal, although admittedly I can't be wholly certain of that. Just trying to understand the histology of the mess I have with one lens.

Maybe I'll be forced to do a microprobe analysis of a bloom using Auger, on my own dime. I think the lens will survive a high vacuum environment.

Nate Potter, Austin TX.

One must know that what you see when looking at "Schneideritis" is the reflection of light between the glass and the air surface who takes place of the detached paint. It is there that the reflection of light takes place. Why the paint detaches from the glass surface is then another question. The outside material, behind this glass/paint layer is not so important. The reflection takes mostly place before the light hits the barrel material.

Leigh
19-Feb-2014, 06:38
One must know that what you see when looking at "Schneideritis" is the reflection of light between the glass and the air surface who takes place of the detached paint.
Absolutely not true in any of the cases I observed.

These were blemishes in the coating of the aluminum, definitely not related to any element edge.

- Leigh

Dan Fromm
19-Feb-2014, 07:59
Leigh, Nathan, if the edge blacking adheres to the glass, as it should, then it will pass no light and corrosion on the inside of the barrel won't be visible from the front (or rear) of the lens.

Nathan, have you removed an affected lens' elements from the barrel and examined them directly or are you looking at the effect through the front of the cell?

BrianShaw
19-Feb-2014, 08:12
... Nathan, have you removed an affected lens' elements from the barrel and examined them directly or are you looking at the effect through the front of the cell?

Good question. I was going to ask both you and Leigh the same thing. As for me... I've only looked at Schneideritis from the front of my lenses when setting the shutter so my theories are extremely limited.

John Conway
19-Feb-2014, 08:20
I'm curious if anyone has ever had a Schneideritis lens reconditioned.

BrianShaw
19-Feb-2014, 08:25
I'm curious if anyone has ever had a Schneideritis lens reconditioned.

When I last spoke to the Schneider west coast (US) repair center, the position they maintained is that there was no reason to do so... and no warranty support even if one wanted it done. I never asked how much a repair would cost or how effective such a repair would be, though.

hoffner
19-Feb-2014, 09:34
As for me... I've only looked at Schneideritis from the front of my lenses when setting the shutter so my theories are extremely limited.

As anyone else - how otherwise would we look at the defect? It is even impossible to see through the lens edge because, obviously, the edge is ground (very rarely polished). Unless you want to disassemble the poor lens to have a look at the detached paint from the outside, which, of course is out of question for obvious reasons.

The Schneiderits is a problem of paint flaking off (for whatever reason) the lens ground edge. It is there it was applied and not on the barrel material.

BrianShaw
19-Feb-2014, 10:07
... Unless you want to disassemble the poor lens to have a look at the detached paint from the outside, which, of course is out of question for obvious reasons. ...

But destructive analysis is sometimes required to accurately/completely understand a failure mode. That is why I ask the same question that Dan asks.

hoffner
19-Feb-2014, 10:21
I understand, Brian, but that is not the OP's intention.

Leigh
19-Feb-2014, 11:29
In the few lenses that I've seen, there were multiple defects spanning a range of distances from the front of the barrel.

Given that these are on an angled surface, as the barrel diameter decreases toward the shutter, they were obviously on the inner surface of the barrel, NOT a defect on the element edging.

BTW, given that the element edging is black, and the barrel in which the elements are mounted is also black, how would we see an edging defect in the first place?

- Leigh

BrianShaw
19-Feb-2014, 11:56
I understand, Brian, but that is not the OP's intention.

Agreed... and it does not appear to be anyone else's intention either. I understand that. Jus' sayin'

hoffner
19-Feb-2014, 14:07
In the few lenses that I've seen, there were multiple defects spanning a range of distances from the front of the barrel.

Given that these are on an angled surface, as the barrel diameter decreases toward the shutter, they were obviously on the inner surface of the barrel, NOT a defect on the element edging.

- Leigh

Schneideritis defect is independent of the angle of lens surface it is created on.





BTW, given that the element edging is black, and the barrel in which the elements are mounted is also black, how would we see an edging defect in the first place?

- Leigh

For the answer see the post n. 27

Leigh
19-Feb-2014, 18:27
Schneideritis defect is independent of the angle of lens surface it is created on.
How many lens elements have beveled edges so they can be mounted in a conical assembly?

Elements have cylindrical edges, and are mounted in cylindrical structures that have tight tolerances.
This is necessary for the element optical axes to remain aligned during the life of the lens.

Even if the edge paint did come off, there's no place for it to go since there's no clearance.

While your assertion about edging may be correct in some instances, it is definitely not correct for all, and
definitely not for the instances that I observed.


For the answer see the post n. 27

The argument presented in #27 is totally specious.

If the air/glass surface reflected enough light for the image to be prominent, the on-axis reflections would be high enough that no light would reach the film.

Disregarding that fact, the edge finish of an element is not smooth.
How could it reflect an image that was in sharp focus?

- Leigh

hoffner
20-Feb-2014, 04:58
How many lens elements have beveled edges so they can be mounted in a conical assembly?

Elements have cylindrical edges, and are mounted in cylindrical structures that have tight tolerances.
This is necessary for the element optical axes to remain aligned during the life of the lens.

Even if the edge paint did come off, there's no place for it to go since there's no clearance.

While your assertion about edging may be correct in some instances, it is definitely not correct for all, and
definitely not for the instances that I observed.

- Leigh


Lens elements have many types of edges - bevels, chamfers, break edges are utilized.

Flaking of the edge paint ((be it due to outgassing, paint ageing, its thermal expansion/contraction, glass thermal stress or yet other reasons) can take place on a micron scale, even a fraction of it only. That is more than enough for the incoming ray to encounter a glass/air surface instead of the glass/paint one and change its bending properties. The "space" can be created by the paint contraction but not necessarily. Modern resin based paints used in the optical industry (as opposed to blackening inks) are so thick (again, on a micron scale) that more than often its thickness must be accounted for in barrel mechanical tolerances. Remember - a few microns or even its fraction is what it takes to accommodate the air space that changes the bending index for the rays optical path.







The argument presented in #27 is totally specious.

If the air/glass surface reflected enough light for the image to be prominent, the on-axis reflections would be high enough that no light would reach the film.

Disregarding that fact, the edge finish of an element is not smooth.
How could it reflect an image that was in sharp focus?
- Leigh

Why don't you give the answer at this question you yourself when you think, it is a barrel imperfection that is somehow seen? Why did you not answer the questions the posts n.29 and n.30 asked you?

When it comes to the sharp image you see in Schnederitis the reason of it is exactly the fact, that the ray is deviated by the glass/air surface (notice the correct order of materials) of the lens element's edge and not something behind it, as you and Nathan think. That also explains why the defect is often seen as having silvery appearance like bubbles in water.

That being said, I would like to reiterate the question aimed at you in the n.29 and n.30 posts at which neither you or Nathan gave an answer.

Nathan Potter
20-Feb-2014, 11:33
Dan and Brian, I've taken a bit of time to look more closely at the one lens I have that shows the schneideritis effect. That is an older 135 all chrome componon enlarging lens. Yes removed the front element per above questions. The body of this lens appears to be all brass but shows extensive schneideritis when viewed thru the front element. Highly visible thru the front element when viewed at 25 and 50X with a binocular microscope (Wild M3). I think I convinced myself that the effect is confined to the beveled edge of the front element possibly where the black edge coating has worn thin to reveal a ground edge glass in spots that are about 2 to 100Ám in diameter, (used a calibrated eyepiece reticle to measure). So Dan is on the right track here. Since the edge is captive one could assume there would be no contamination to the optic surface. But close examination reveals tiny bits (specks) emanating out from the lens edge, well into the optical path. These look like grit from the ground edge; higher in concentration nearer the edge then dwindling to few about 1/4 way to the lens center. Probably little to no effect on the lens performance.

Next I looked at a 110 SSXL (not disassembled) which at first (with the unaided eye) showed no schneideritis; but thru the front element showed many spots of whitish pinprick blooms on the blackened aluminum housing under the from element. I think this had to be on the aluminum since the machining showed the stepped contour for internal scattering reduction. The size of these white spots were small from 5 to maybe 25 Ám; probably creeping schneideritis. But I've seen worse cases of this in the blackened aluminum housing on a few other lenses I've used.

I think there are at least these two causes of schneideritis, unrelated to each other in origin but may appear similar to the unaided eye. Certainly a cause for confusion by me and others.

Nate Potter, Austin TX.

hoffner
20-Feb-2014, 12:28
Thanks, Nathan, for the interesting report.
Well, it is not anything strange that a paint can flake off the aluminum/brass barrel material as well as off the glass. Logically, you couldn't see through the lens the flaking on the barrel when there was no flaking on the lens elements edge. Therefore Schneideritis is normally seen when the flaking takes place on the glass element paint.

BrianShaw
20-Feb-2014, 12:53
Very interesting. Thanks Nate.

Dan Fromm
20-Feb-2014, 13:57
Nathan, thanks very much for taking the trouble.