Originally posted by Marc Sabatella If you're not aiming at a well-designed focus test chart, there's a very good chance that what you're seeing isn't backfocus but simply the camera choosing to focus smewhere other than where you wanted because the focus sensors are too broad to allow you to pinpoint focus..
Very legitimate point, but when I was using it, I was doing head shots, and they were not in focus, but the wall behind them were. My other lenses doing basically same shots had no issues. During my adjustments, the focus did change between regular focusing and live view, and I read that's a good indication that the system is off. Now it doesn't do that. Just need to now do some more "real life" shooting to see how it is now.