150XL Internal Problem...Any ideas

[Tom Stanworth]

I have a 150XL which I bought used and was fine. I have been overseas and so it has not been used, but stored with the shutter exercised every 2 months. I noticed on my last trip back home that the lens had developed a kind of faint whitish grey residue inside the front assembly. It is most definitely not fungus (which is random and snakes all over the place as expected of slime mould) but as if a fine powder had been brushed very gently in whisps on one of the internal elements. It seems to follow the perimeter contour of the lens in whisps that looke like they have been brushed on ever so gently kinda like the stuff they use for fungerprints.

If my memory is not failing me, there were reports of some Schneider lenses having faulty (cement?) which caused a residue to settle on the elements, which could be cleaned off with an internal clean at Schneider. Can anyone comment further on what this could be before I ship it to schneider? Yes, I am terrified as this is the most expensive lens I own and I have not even used it! I hope to *&&^%^%*& it is not a paperweight now

 

[archphoto]

Are you shure it is not at the surface facing the shutter ?
If it is internal: ship it, cleaning internal parts of a lens, unless it's an oldie without value, should be done by specialists.

Sorry,
Peter

 

[John Koehrer]

Schneider's have "schneideritis" which is a degradation of the paint on the outside of the group. Usually shows up as white or gray spots along the side of the lens.
Rodenstocks from the 70's(?) have some separation problems.
If it's on the elements facing the shutter it's easy, remove the group from the shutter & clean it, if inside the group ship it.

 

[Trevor Crone]

Tom, I share your anxiety as I too have this lens. It could be a cement/balsam fault between lens elements. I once had this type of problem with a Schneider 65mm Super Angulon which looked like little white specs on one of the internal lens elements.

Another type of problem is flaking of the anti-reflective paint.

Any chance you can get the lens to a dealer specialising in LF for an inspection?

 

[Tom Stanworth]

thanks all. Its not around the surface where the element touches the barrel like schneideritis (which I have seen on many older lenses). This is on the face of the glass, inside the front assembly somewhere and not on any external surface. Rather than specks it is kind of a smokey white/grey coating near the margins and appearing to run around the circumference. No speckles or spots, but almost appears to have lines, as if applied with a brush, following the margin. I guess the lines could be tide marks if something has vaporised inside the lens (such as cement) and deposited on the elements. I guess I will have to ship it to Schneider as it is completely unusable as it is.

 

[Trevor Crone]

It could be that moisture has got inside the lens, evaporated and left 'tide marks', which usually leave circular marks?

Whatever it is I think it will need dismantling to clean it correctly.

 

[David A. Goldfarb]

Modern lenses use UV cured cements rather than the Canadian balsam that is found in older lenses, so separation is less common than it used to be. Time will tell, of course.

It's probably something like oil or some atmospheric pollutant that's deposited on the lens that can be relatively easily cleaned.

 

[Mike Walker]

150XL

Hi Tom
Please call me on Monday.
I would like to help you with your 150XL if I can.
Mike

 

[Tom Stanworth]

Hi Mike! I have not seen you for a while! I am now back in Afghanistan (sadly) but will be in touch soon. Thanks so much!

Trevor, Beats me how moisture could have gotten in (my other lenses, incl two other XL lenses stored in the same bag) are fine. It is possible I suppose and would be in keeping with the whisps. There is lots of dessicant in there so if there was some moisture lurking in there when at some point, it wont be there now. I hope!

 

[Steve Hamley]

http://www.largeformatphotography.info/forum/showthread.php?t=15123&highlight=80mm

Also seen in the 150mm

Steve

 

[Tom Stanworth]

Thats sounds SMACK on. None of my other lenses affected and stored the same. Appeared out of nowhere, within a couple of months and it is severe enough to render the lens unusable. I knew I had read about this with the 80XL but had no idea others were affected. Fantastic guys, thanks so much.

 

[Mike Walker]

150XL

Hi Tom
Please email me the serial number of your lens.
Mike