I have been noticing that many of my captures, especially at F2.8 (narrow depth of field) at 200MM on my 70-200 lens seemed a little soft. I first just blamed it on my technique. Then I saw repeated shots of say wildlife surrounded by gravel or grass and it was quite clear that my camera was focusing a bit in front of the intended subject.
After doing some research on micro focus adjustment procedures I can across Jeffrey Friedl's 5 year old blog on his approach which hit home with me.
Yesterday I printed out a few of the focus charts and gave it a shot on my 7D with my 3 different lenses. Following his instructions it was very easy to quickly see exactly where my camera was focusing. Both my F2.8 70-200mm and my F2.8 17-55mm lenses were front focusing. My 10-22 wide angle was spot on and did not need to be adjusted. My 7D allows you to micro adjust the focus for individual lenses so I did that for the two giving me a problem.
Both lenses were verified with re-shooting the focus chart as well as field testing on subjects that would easily show up incorrect focal planes. It took a +9-10 back focus micro adjustment to get these lenses to consistently lock on accurately. Now all my lenses are spot on and if I get fuzzy shots, I now know it's a personal problem.
I'm just throwing this out there for folks that may feel their gear seems a bit off on auto focus and want and easy way to verify if you have a gear issue or not. I don't know if all DSLRs have a micro focus option but if yours does, this is an easy and accurate way to make those adjustments.