Quote Originally Posted by BrianShaw View Post
While I agree with EvH immensely that many (most?) CLA does not include rigourous "A" I feel obligated to mention that 30% error is for some professional shutters within the original specification.
It seems to me that most shutter overhauls clean and lubricate with the assumption (good in most cases... in my experience) that those two activities will restore the original capability and specs.

For me a half-stop is still relatively insignificant and the most useless tool I -- personally speaking -- could ever buy is a shutter tester that might evoke my currently-repressed shutter-speed neurotic tendencies/anxieties.
Yes, this is correct. It's also unacceptable, I've always felt it was a weasel tolerance. I need to know that my exposure will be what I expect; transparency film will not tolerate much error, and black and white is the same if you are using it's entire tonal range.. Is 30% error acceptable in a lightmeter? No. Aperture calibration? No. Then why on shutter speeds? I've never had a problem getting the speeds within the 10 to 15 percent tolerance I mentioned above, with the exception of the one or two higher speeds on leaf shutters, which will be consistent but slower than the marked speed.