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09-02-2007, 02:14 PM   #1
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AF TC with m42 lens?


I just read something about AF-TC that makes me wonder... it was that one could use an autofocus-teleconverter on a manual focus lens, and then have an Autofocus result.


I have a 300mm F/4 SMC Takumar lens. As you will know, it has screw mount. Can I turn this jewel into an autofocus 600mm F/8 by buying an AF-TC? (the M42/K adaptall is already on the lens)

If I do so, is there much quality difference between teleconverters?

What's your experience?

Thanks for looking into my questions!


09-03-2007, 03:36 PM   #2
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Only the Pentax-F 1.7x AF Teleconverter will work for what you propose. For M42 lenses you will need to place a little bit of aluminum foil covering the contacts for the TC before it will focus. Strange, but it works.

(I have used this combo with my Super-Takumar 300/4, and in good light it works fine. Like all TCs images are slightly softer, and there is a bit more CA, but not enough to kill the image.)

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