Hello everyone!
Recently purchased a Canon EF 70-200mm f/2.8L Is II USM that I'm using on a Canon 7D. This is a learning curve for me. In the image that I have posted my question is, why are his rear legs in focus but not his head. I use the center focus point and my settings were as followed.... f4 shutter 1/1600 ISO 500 at 123mm in AI SERVO. I was told that f4 would be the sharpest f stop for this lens. Any help would be greatly appreciated!