Re: EOS Missing EXif info

[NK Guy]

Actually, the timing for this question is funny because an online benefactor mailed me a defective focus motor and drivetrain from his EF 50mm 1.4 lens the other week, knowing I was interested in such stuff. It's interesting to see how the full-time manual works - there's basically a brass and nylon friction clutch which permits the manual focus ring to turn while not affecting the motor side of the drivetrain. (the 50mm was for a long time the only EF lens with full-time manual which did not use a ring USM motor - it uses a USM micromotor)

Anyway. There's a curved plastic piece (segment of an arc) with three copper stripes on it, clearly a contact mechanism. The stripes are in a series of patterns and it looks to me like a distance encoder. However, it also looks like one which is only capable of returning 4 separate distance ranges. It's hard to tell from the photo online, but it does sort of look like the one in Steve Weixel's lens tour of a dismantled 28-105:

http://www.photoscene.com/sw/tour/inside.htm

So, I really don't know. I know some of the older first-gen EF lenses can't return distance data, but it sort of *looks* to me like the 50mm 1.4 should be able to return *something*. Interesting if it doesn't.

- NK Guy

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