workerdrone Offline Upload & Sell: On
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You need a better target - you think you know where the focus is here, but you REALLY don't. And I don't either.
I just fine tuned all of my lenses today on the D7K, they range in needs from -2 to -20, so my D7K definitely has a back-focusing issue.
However, with all of them tuned, the AF is very accurate - in fact most of the time I can't do any better in live view.
Since they're all within the range of adjustment, I'm not concerned about the body since it's out of warranty and everything works 100% now - it would be a waste of time and $ for me to send it in.
This is why the mfr.'s include the feature, because they know it's needed - but you need to be systematic about it and get repeatable results to get it right. I wouldn't be concerned at all if your body/lens combo back or front focuses - as long as it's within the range of adjustment and it's consistent, they have already given you the tools to fix it.
I built a 16x20 stiff cardboard target, covered it with a "bar code" of black duct tape strips in different widths, placed it on the lawn, and took test shots at realistic distances and good shutter speeds, wide open and on a monopod, estimating sensor plane parallel to target, re-AF'd for each shot, then pixel peeped at 100% on my big monitor to see what adjustment I might need, looking for the blades of grass in the plane of the target to be in focus.
Today I received a used lens align tool and did it the 'right' way, ensuring dead on alignment of the target and recommended distances for each lens with a tape measure between two tripods.
Turns out my homemade method worked just as well, it just took a bit longer to get there
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