If you have perfect/acceptable left AF with D800 and 24-70mm, I need your help

Started Jun 28, 2012 | Discussions thread
mrwilkins
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Re: If you have perfect/acceptable left AF with D800 and 24-70mm, I need your help
In reply to D800, Jul 2, 2012

I'd consider my camera's focus performance acceptable, though not perfect. Here are some test shots with a 17-35/2.8 set at 35, at f/2.8. Distance is about 2.5 meters.

Here are 100% crops of center, left, right respectively:

The left hand side image is definitely blurrier than the other two. However, I suspect that this is at least made worse by the lens itself, because the blurring is much more horizontal than vertical, suggesting astigmatism in the lens.

Also, I hand-focused using live view and got this result, which is very similar:

Regardless, even the left hand side images are sharp enough to be usable for most things, and shooting wide-open with even a good zoom lens is going to reveal less than critical sharpness as one gets away from the center. I don't really have a good way to test whether the camera or the lens is the source of the issue I see here, but the worst-case in these pictures is nowhere near the OP's problem.

EDIT: It is the lens, not the camera. (Or, at worst, it's a camera/lens interaction issue, but I think it's the lens.) I repeated the test using my 35mm f/2 AF-D prime and got these results.

Those images are all quite sharp enough for my satisfaction.

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