Yeah, it could be much sharper. I tried to open to a sharper f-stop (hence the f4) but the bird was in the shade making the conditions dark. Also, it is my understanding, which could be wrong, that the auto focus works by ranging and comparing straight lines. In the conditions I was in, the auto focus "looked" at, and focussed on, the base of the feeder, NOT the nuthatch. In times like those, I prefer to manually focus, but this is a quick shy bird, I had the camera on auto drive, and no time for such things. He'll be back.