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03-19-2010, 01:40 AM   #1
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Using SR with TCs and/or extension tubes

When the Shake Reduction is turned is on and I'm using a teleconverter should I give the camera the focal length of the lens alone, or the focal length of the lens multiplied by the TC's magnification?

E.g. assume I'm using a 50mm lens mounted on a 1.7 TC. When I switch the camera on the SR system wants me to dial in the focal length of the length of the lens. Should that be 50mm, or 85mm (50*1.7), or something else?

Also, for the purposes of the SR what effect do extension tubes have? If I'm using the 50mm lens on a 31mm tube, should I tell the camera that it's a 50mm lens or an 80mm lens, or something else again?

03-19-2010, 02:50 AM   #2
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QuoteOriginally posted by Spazmatazz Quote
When the Shake Reduction is turned is on and I'm using a teleconverter should I give the camera the focal length of the lens alone, or the focal length of the lens multiplied by the TC's magnification?
Use the focal length of the lens multiplied by the TC's magnification.

QuoteQuote:
Also, for the purposes of the SR what effect do extension tubes have? If I'm using the 50mm lens on a 31mm tube, should I tell the camera that it's a 50mm lens or an 80mm lens, or something else again?
I just looked at many discussions and calculations of this, but the rule of thumb WITH PRIMES is simple: add the extension to the focal length. In your example, tell SR it's 80mm. But my K20D will only accept 75 or 85, and your K200D is probably the same. So get as close as possible.

With zooms, it's a bit fuzzy. I *think* you add the extension to the focal length you're using, not to the minimum or maximum of the lens. I'm not sure if there's a difference using old push-pull manual zooms, and twist-to-extend zooms.

EDIT: My K20D manual says, "The Shake Reduction function may not perform as expected when shooting at close ranges." Gee, thanks.

Last edited by RioRico; 03-19-2010 at 03:12 AM.
03-19-2010, 06:56 AM   #3
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Nice info and thanks for the warning.
03-19-2010, 07:11 AM   #4
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Thanks, that's good to know.

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