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05-25-2013, 04:56 AM   #46
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My friends, is it possible to tell me if there's any possible way to convert SMC Pentax A f/2.0 manual focus to AF ?
Thank you very much.

05-25-2013, 05:34 AM   #47
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QuoteOriginally posted by PedroCosta Quote
My friends, is it possible to tell me if there's any possible way to convert SMC Pentax A f/2.0 manual focus to AF ?
Thank you very much.
I'm not sure there is a way to convert any manual focus lens to AF, or if it would be any good if you could. My MF lenses have a long slow focus motion, that makes it easy to get an accurate focus, you see it coming, coming, coming... ah , there it is. My AF lenses have a much shorter distance to travel. WHen you manual focus them it's really hard to tell where the exact spot is because they go by it so quickly. One is designed for a guy looking through a view finder. The other is designed to be fast when powered by a battery operated motor. Even if you could do the conversion, focusing would be extremely slow. The next problem is auto-foucssing is all done with internal components, and those are incorporated into the design of the barrel of the lens.

So long story short, no, for more reasons than I've mentioned. That isn't to say it couldn't be done. I can think of a couple solutions that involve the manufacture of some fairly complex components and then inserting your barrel inside a larger barrel with the necessary components. I can't imagine that costing less than just buying an AF lens, or even 5 AF lenses. You'd need a guy with some serious skills.
05-25-2013, 05:43 AM   #48
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Her are some A-400 and 1.7 TC shots, I actually prefer turning the AF off and using manual focus. That darn AF can't tell what I'm looking at.













05-25-2013, 05:54 AM   #49
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Thank you very much

05-25-2013, 10:08 AM   #50
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QuoteOriginally posted by normhead Quote
That darn AF can't tell what I'm looking at.
Right! For birds in trees, MF is usually preferred.
06-22-2013, 03:21 PM   #51
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Taken with K-r and Sigma EX 70-200mm f/2.8 DG APO Macro HSM II:

f/4?, ISO 400


f/2.8, ISO 200



Taken with K-5 and Pentacon 300mm f/4:

ISO 400
06-22-2013, 03:35 PM   #52
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A few more, A-400 5.6, Pentax 1.7 TC





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