Strange behaviour of a Linhof Schneider 90 XL

[Jac@stafford.net]

[...] If we are talking about Linhof's rigorous testing: What are they testing exactly? Bob described somewhere else that they have a certain light pattern which is used to determine performance. Is it done wide open? Do they really care for the position of the aperture blades whether it is in z or radial direction? Doesn't a lens manufacturer like Schneider have more specialized testing methods?

Your answer is in your question. You do not know enough about testing, and more important you do not take into account the damage a lens can incur after leaving the manufacture, or the damage occurring from the previous owners. Please do not assume lenses are impervious to damage after the manufacture.

[Luis-F-S]

Who said that that was condition when it was originally sold?

+1! If you didn't buy it new, then you have no idea how it left the factory, or what's happened to it since then! L

[Mark Sampson]

I have a Linhof-branded Schneider Super-Angulon (a 121/8) that dates from 1957, and long ago had a 90/8 SA of similar vintage. We don't know how old your lens is; a lot can happen to a lens in 50+ years. I have a tough time seeing your problem as a manufacturing defect.

[Grumium]

Yep, you are probably right. We will never find out what happened to the lens (age 15) before. Best of all: it isn't mine ;-)

[Old-N-Feeble]

As a side note: If one buys a used lens then try to get a return privilege within a reasonable time frame... say two weeks in-hand.