Originally posted by schmik I believe AF was on the card. But I can't be 100% sure.
I don't think it's *possible* to be 100% sure based on the full size image you posted - the post/pipe the card was mounted to might have been the actual focus target chosen by the camera even if you specifically chose center point. That is, the card does not appear to cover the entire center AF sensor.
I agree that what you are seeing is definitely a matter of the f/2.8 shots being out of focus, but I certainly would not be leaping to any conclusions that there is a malfunction here. You need to repeat your test using a setup in which the camera cannot possibly choose any focus point other than the intended one (do that by choosing a larger target, or by shooting from a shorter distance).
Quote: I just double checked my shots with the fisheye (only other decent auto focus lens i own). They are soft soft soft wide open too. I just allways assumed it was the lens.
With an extreme wide angle lens, it's next to impossible to force the camera to focus on any single object, since most objects will be rendered much smaller than any of the AF sensors. Plus DOF is pretty darned wide. Which is to say, it wouldn't seem to likely to me that this is what is going on. But again, you'd have to do a controlled focus test (discussions of this topic are pretty much a weekly event here; also jus browse around the net) to be able to say for sure.