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06-08-2008, 06:27 PM   #1
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Af Tc

Silly question, but how does an AF TC work?

06-09-2008, 11:40 AM   #2
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Like this.. Some may actually have a linkage that accepts the drive slot of your camera's AF drive screw and in-turn powers the mechanical AF of the lens via this linkage. Newer lenses that have SDM focusing motors simply need the electrical contacts to pass the focus information and power the lens in a non-mechanical way.
06-09-2008, 01:18 PM   #3
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Okay...

For some reason, I got the impression that an AF TC would allow AF on MF lenses. So that's not the case? I mean, it sure sounded far-fetched.
06-09-2008, 01:24 PM   #4
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QuoteOriginally posted by joefru Quote
Okay...

For some reason, I got the impression that an AF TC would allow AF on MF lenses. So that's not the case? I mean, it sure sounded far-fetched.
It's not far-fetched if you have Pentax AF 1.7X - it does autofocus manual focus lenses, within limits. On long focus lenses, you have to set rough focus first and let the converter fine tune the focus. The screw drive engages the movable elements in the converter, just as it does in a screw drive AF lens.

06-12-2008, 08:11 AM   #5
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Thanks. I figured it must be something like that. It would be like magic if you could MF to infinity and try macros.
06-13-2008, 12:56 AM   #6
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QuoteOriginally posted by Canada_Rockies Quote
It's not far-fetched if you have Pentax AF 1.7X - it does autofocus manual focus lenses, within limits. On long focus lenses, you have to set rough focus first and let the converter fine tune the focus. The screw drive engages the movable elements in the converter, just as it does in a screw drive AF lens.


One of the Pentax TC X 1.7 recently went off on ebay for Au$365 mad frantic bidding in the last 10 min push the price from 220-365


cheers
06-13-2008, 12:57 AM   #7
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How is AF-TC co-operating with a AF lens? Anyone tried?
06-13-2008, 04:17 AM   #8
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Sadly if you want one [Pentax TC X 1.7] thats what you have to pay these days.

But its now mine. lol

Wal'

actually it was $362.00

QuoteOriginally posted by cupic Quote
One of the Pentax TC X 1.7 recently went off on ebay for Au$365 mad frantic bidding in the last 10 min push the price from 220-365


cheers



Last edited by wwwmorrell; 06-13-2008 at 04:51 AM.
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