Something isn't right with the focusing mechanism with this lens or it doesn't like being paired up to a Nex camera. Although I use the peeking function I get the feeling that the image is misfocused. Not all of the time but in a lot of cases. No I do not have this problem with other lenses so I will dismiss the arguement that it's the photographer that is the problem in this case. I know the DOF is shallow at f3.5 but normally I stop the lens down to f5.6 or f8.

The image above is sharp whree I focused the lens, namely on the moss growing on the branch. I took three images of this just to make sure I got one and two out of three images were not in focus.