Not quite “the most anal-OCD masters of the universe” (with pictures)


Manufacturing variation affects all lenses from all brands – the only difference is the tolerance levels considered acceptable.

Photographers don’t need the inspection cartel to make them obsessive, but they deal with it differently.

“…’Bad lenses are rare, but the people who examine them with anal zeal are not and this article won’t cure them, sad to say.’

So very true, especially in a hobby that attracts the most anal-OCD masters of the universe. Yes, I am including myself in this group.”

Says a comment on an article about variations in camera lens performance.  It’s an informative piece:  Variation facts and fallacies.   But it wouldn’t satisfy the cartel.

Six Sigma gets a mention in the dozens of readers’ comments, but not ISO management standards.  Not even ISO manufacturing standards at the time of writing.

A single lens (circled) was re-tested on eleven camera bodies (red boxes and blue diamonds) from two different serial number series. All were brand new from box

The author concludes:

“So What’s the Point of All This?

The main points are fairly straightforward:

1) Every lens and every camera exhibits slight variations relative to its twins that are detectable, but rarely significant.

2) Variations that wouldn’t make the slightest difference in a print may seem quite different when the numbers are presented in a lens review. And, just because one copy of lens X is sharper than one copy of lens Y, doesn’t mean they all are, or that they all will be in your camera.

3) Occasionally, an acceptable lens mounted to an acceptable camera combine their variations in a way that makes them unacceptable together. The lens may be fine with a different camera, and the camera fine with a different copy of the lens. 

4) Really bad, soft, out-of-acceptable range lenses do occur. They are fairly rare though and easy to detect.

5) Camera autofocus is more variable and less accurate than you think.* “

(Emphasis added.)

Many areas of pathology operate with wider tolerances than precision engineering, and not only for pre- and post-analytical reasons.  Maybe photographers deal with variation better than pathology inspectors after all.  Could this have analogies that should be food for pathologists’ thought regarding uncertainty of measurement requirements?

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