I just got the 40D and a Sigma EX 70-200 2.8 APO DG HSM Macro for it, along with 2 other lenses. When I attach the 70-200 the auto focus does not seem to work. I've played around with the focus mode switch and it has no effect. Any suggestions that do not involve buying something new?
Battery level is critical on this thing; if it falls much below 1/2 full, you may as well change it out. Mine decided to stop focusing right in the middle of a wedding, while I was waaaaaay in the back - all I could do was work my way to the front while changing lenses.
It may last until the battery is nearly dead, but you WILL run into issues if not prepared. I always have a backup battery in my pocket when shooting this lens.
Battery level does not seem to be an issue, I charged one of my batteries for more than 12 hours last night and even with that it still don't work. Any other suggestions please?
Did you order online or purchase locally? If locally, can you try another copy of the Sigma lens on the body and see if it works? If not, I'd start to wonder if this Sigma lens is going to need rechipping for the 40D. Sigma does not have a license for the Canon mount. They reverse engineer the interface, so every time Canon tweaks the interface, Sigma has to rechip their lenses.
I have the exact lens, except in a better (Nikon) mount. Mine did the exact thing when I first got it.
It makes a noise like it is trying to focus but is stuck? I turned the camera off, manually focused back and forth, then turned it back on and it was fine. It did that to me 3 times on the first day and has been fine ever since. (about 3 months)
It might or might not. Depends on when the firmware for each lens was written and what changed in the interface. If Canon has made a major change in the interface, it's more likely that all Sigma lenses would be affected. A minor tweak could possibly affect only some models, but I'm hypothesizing here without much hard information.
Your problem may in fact turn out to be something different altogether.
I have the exact lens, except in a better (Nikon) mount. Mine did the exact thing when I first got it.
It makes a noise like it is trying to focus but is stuck? I turned the camera off, manually focused back and forth, then turned it back on and it was fine. It did that to me 3 times on the first day and has been fine ever since. (about 3 months)
It makes no noise at all and doesn't even appear to be trying to focus.
I don't have the 70-200, but I have the Sigma 105 f2.8 and on this lens if you pull the manual focus ring forward (away from the camera) it takes it out of Auto Focus mode, could the 70-200 you have, have the same feature? If it does, just pull the focus ring back towards the camera to re-engage. You might check. If all else fails I'd PM Hotpasta, he has that lens, and quite a few other Sigmas, he might know.
I don't have the 70-200, but I have the Sigma 105 f2.8 and on this lens if you pull the manual focus ring forward (away from the camera) it takes it out of Auto Focus mode, could the 70-200 you have, have the same feature? If it does, just pull the focus ring back towards the camera to re-engage. You might check. If all else fails I'd PM Hotpasta, he has that lens, and quite a few other Sigmas, he might know.
I have a Sigma 28-70 f/2.8 EX DG and it is not behaving on my Canon 40D. Pressing the shutter button for focus makes the lens jitter back and forth quickly before settling on OOF. Retrying might get focus but often settles on OOF again. I've even experienced the jittery focus action without stopping until I release the shutter button.
I have a Sigma 105 f/2.8 EX macro and it works fine on the 40D, as do all my canon lenses.
I'm hoping that a rechip will solve the focus problems.
Has anyone talked to Sigma about focusing issues with the 40D?
Find a friend/shop with another camera. Try another of the same lens on the camera, and try your lens on another 40D. I have this lens on the 400D, and it's OK.
Oh, and as nobody else has suggested it, did you check the MF/AF switch? :)
I talked to sigma australia and they hadnt heard of any issue so I used it on my work camera - a 350D - and it didn't work either, replacement is on the way, hopefully I get it today before I go to cover a big sporting event this weekend.
