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05-07-2009, 07:24 AM   #1
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Sigma 20 1.8, nails close focus, back-focuses at a distance. What to do.

All in all, I really like this lens. Despite reviews to the contrary, I have found it to be respectably sharp wide open, as long as the focus is nailed. But, it does consistently back-focus at any distance longer than arms length. Closer, it nails it. I'm inclined to believe it has more to do with the K20d's not-so-stellar AF system, as apposed to the lens itself...

My dilemma is this; do I try to correct the auto focus for subjects farther away, likely causing forward focus on close subjects, or just say eff it, and learn to manually focus better? The latter being what I have done mostly to this point.

I feel like I know the best answer here, but would like some others' input as well...

05-07-2009, 11:38 PM   #2
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Location: Bremen, Germany
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Things like this normally happen, when the camera AF is not perfectly calibrated.
You could send the camera in for an AF calibration.

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