Tue 30-Oct-12 05:45 PM | edited Wed 31-Oct-12 08:23 AM by kingsgraphic
You know, I read this thread and thought "there's no way you can get sent three different bodies and get the same fault in all three". However, since then I've scouted around on the internet, and found multiple examples of users citing the same problem. One guy is on his sixth body!
Conclusion: there is a problem out there, but most of us don't have it. Maybe there was a bad batch; maybe the calibration equipment in Nikon Q&A was 'off' - (remember the Hubble Telescope and the focus problem due to incorrect calibration gear in the lab?) If NASA can get it wrong for sure Nikon can.
Addendum: Since reading the thread I've printed the chart off myself and, although being always happy with the images from my D7000, find that according to the focus chart, I have an offset of -13. My feeling is that most D7000's, and probably all DSLR's AF systems, have this offset from new. Why? Well to allow for manufacturing tolerances. If the AF calibration was attempting to get it spot-on 'zero' every time, then some cameras would have front-focussing all the time. In a portrait situation this would mean that no part of the image was in focus. Offsetting backwards means that part of the image is always in focus. Why so many seem to be outside the range of offset is probably down to sloppy calibration or equipment fault. I'm guessing that for most sitations the effect is lost in the DoF.
Something else I noticed. In 2011 the Nikon Thailand factory was flooded-out. In 2012 it was re-equipped with new, 'faster', equipment. My camera is a 2011-built model. From what I've seen those with the excessive offset problem are 2012 models. A coincidence?