I have an 100-400 that I use on a 60D for wildlife. I have been spending quite a bit of time in a prarie dog town taking photos of the dogs and burrowing owls. On my last trip I also took a 7D body that I had rented to compare to the 60D. I got real flustrated with the quality of my photos as most appeared very soft. The dogs were anywhere from 15 yards to 75 yards. I focused on the head, the eye if they were close enough. Both cameras had the same result. I finally tried putting the focus on the ground right at the dogs feet and it was like night and day as far as sharpness is concerned. The photos became sharp enough to count the wiskers on the dogs. Has anyone else experinced this with the 100-400? I really like the range, size and quality build of the 100-400 but have noticed lots of bird photos were not very clear. I tried using the MFA on the 7D and the best setting for the 100-400 was 0. Shots were taken in bright light, Iso 200, shutter speed in the 1000-1200 range with f7.1 to f8. Would like to figure this out as there is often not enough time to find a close item to focus on.