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DPChallenge Forums >> Hardware and Software >> Sigma lens issue
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09/13/2007 11:07:54 AM · #1
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?
09/13/2007 11:10:03 AM · #2
have you used the lens on another body?

is this related to LiveView (my understanding is that if LV is active, then autofocus is not). But could be wrong, I don't have a 40D.
09/13/2007 11:17:03 AM · #3
No I haven't used it on another body. Perhaps when I get my work camera - a 350D - back I'll give it a go.

Live view does not seem to affect it, just turned it on and used it then turned it off, still no dice.
09/13/2007 11:18:45 AM · #4
And AF works fine on my EF 50mm prime.

And on an EF-S 18-55.

Message edited by author 2007-09-13 11:20:53.
09/13/2007 01:04:15 PM · #5
I have the same lens, but for Nikon.

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.
09/13/2007 07:50:57 PM · #6
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?
09/13/2007 08:11:34 PM · #7
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.
09/13/2007 08:14:21 PM · #8
Got it online. I was beginning to have the sinking feeling it was something like that.
09/13/2007 08:23:25 PM · #9
Originally posted by Delta_6:

Got it online. I was beginning to have the sinking feeling it was something like that.


Migh be time to give a call to Sigma. If it is that, they should already be aware of it.
09/13/2007 08:27:30 PM · #10
So I guess it would apply to all Sigma lenses?
09/13/2007 08:32:29 PM · #11
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)
09/13/2007 08:33:18 PM · #12
Originally posted by Delta_6:

So I guess it would apply to all Sigma lenses?


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.
09/13/2007 08:34:11 PM · #13
Originally posted by basssman7:

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.
09/13/2007 08:52:18 PM · #14
I just called Sigma's agent here in Australia and they are not aware of any issue.
09/13/2007 09:24:48 PM · #15
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.
09/13/2007 09:28:21 PM · #16
Originally posted by CapeSail:

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.


Thanks, focus ring doesn't move like that.
09/17/2007 09:19:23 AM · #17
I do have the exact same combination.
I.e. Canon 40D and the Sigma 70-200 2,8 HSM Macro...

...and the AF works like a dream...

must be something wrong with your lens...or the 40D...

It is a BIG differens in AF-performance compared to my 20D.
09/24/2007 10:54:14 AM · #18
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?
09/27/2007 09:40:06 PM · #19
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? :)
09/27/2007 10:21:39 PM · #20
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.
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