I personally can\'t believe that 31 out of 57 people that responded to this pole have no focus issues at all with this lens.
I bought 3 copies of the lens myself, and none of them focused properly. I decided to send my 3rd copy in to Sigma for calibration. Sigma sent it to CRIS in AZ to do the work. CRIS told me the lens was within factory tolerance, but they would calibrate it to my camera body. So, I sent them my 5D body. Got it back, and it was better, but still off. Not only that, now it was focusing very slowly, and stalling before achieving focus lock. I sent it back to CRIS. The repair log says they made some type of repair to the HSM motor and lubricated the barrel. Got it back, and focus speed was fine again, but the lens was still off. This time I called Sigma in NY and made arrangements for them to calibrate the lens...again to my 5D body.
My copy still front focuses at close distances (MFD to about 6 feet). I\'ve learned to work around that. I should note that in all instances of my comments about not focusing properly with all the copies of this lens that I tried I am talking about wide open performance.
After everything I\'ve been through I find it hard to believe that any copy of this lens focuses perfectly. If you shoot stopped down it isn\'t an issue, but again, I\'m talking about shooting at f/1.4.
I shot with the Canon 50 f/1.4 for almost 2 years, and much of that was wide open. In my experience my Canon was sharper and more consistent wide open at close distance than any of the Sigma copies I tried (using auto focus without manual tweaking). To put things into perspective, focus accuracy/consistency wide open on my Canon wasn\'t stellar either, but better than the Sigma.
With all of that said, I have to admit I love the way the Sigma renders. It is a love/hate relationship I have with this lens. I sold my Canon and kept the Sigma. I curse at the Sigma regularly, but when it hits focus the images it produces are wonderful.
I\'m typing this late at night, and don\'t have my serial number handy. I\'ll edit this post later and add the serial.
Mark
Dec 10, 2009 at 12:20 AM
Previous versions of Mark Zwiesler's message #7872819 « Sigma 50/1.4 AF Issues [pt.III] UPDATED »
