I have a Sigma 30mm f/1.4. I use it primarily on a 7D (And often on a 60D, too).
The lens seems to focus perfectly, up to a certain distance (for argument's sake, we'll say 10 feet). Within that distance, the lens is generally spot on, sharp and get the focus right.
However, when I go above that distance, the lens seems to have real issues with missing focus. Sometimes it's right, vast majority of the time it's wrong.
So I sent the lens off for calibration with our Sigma dealer (who are fantastic to deal with so far) and I got it back today. Sigma dealer reckons there's a bit of front focus, which they believe they fixed. Said they took a few random shots and it should be grand now.
However, the lens still exhibits the same issues (now, i do genuinely believe that the Sigma guys think they got it right, as, if I were checking a lens' focus ability, I'd get really close to my subjects so the DOF would be shallower, so they probably didnt really try and distance shots at all, which is understandable).
I was wondering if anyone else has had this issue, and if so, have you had it fixed? Did you have to re-send for calibration again (I'm guessing I'll be needing to re-send with the camera bodies, but seen as the lens is spot-on under a certain distance, and exhibits similar traits on both bodies, I'm under the impression it's the lens at fault).
Anyone any experience of this?