Problem Canon 20D and Sigma 24-70mm/f2.8 lense

[kcrouth]

HELP!!!

I just purchased a Canon 20D and a Sigma 24-70mm F2.8 EX DG MACRO lense to go with it. I have no other lenses. When I take the camera out of it's case and turn it on, it powers up but will NOT autofocus nor will the shutter operate. I can turn it off and on and the same thing occurs. The only way I can get it to operate properly is to remove and replace the lense.

Thinking that it was a lense issue, I exchanged the lense for a 2nd one of the same. I still have the same problem. I do not have any other lenses to try, nor to I have another Canon camera to try the lense on. I did take it to local camera and they tried a Canon lense on and it worked, but that really proves nothing since if I mount the Sigma lense on the camera, it works. It only fails after being powered off and set aside for a while. I also tried (after removing and replacing the lense to get it working) letting the camera power itself off. When I powered it back on by touching the shutter release, the camera was still functioning.

My 20D firmware is 2.0.2. I don't know what vintage the lense is, except that it's new.

I don't know what else to try. My RMA number with B&H Photo Video expires in about a week and I need to make a decision on what to return to them. If I don't figure it out, I guess I'll send it all back for a refund.

kevin

ps. another symptom is that when the camera is in the non-functioning mode (powered on but not autofocusing nor shuttering), the F-stop readout reads 00 (two zeros).

[kcrouth]

pps. another clue: removing and replacing the battery will correct the issue. Any ideas?

[gparr]

I keep that very lens on my 20D as my primary lens and it has worked flawlessly for me. Since you've already replaced the lens once, the problem seems to be the camera. I'd consider replacing it.
Gary

[kcrouth]

I got this reply on another Forum. What firmware does your 20D have? I think it's an incompatibility between the camera f/w and the lense f/w. I've heard that Sigma can "re-chip" the lense and make everything work together.

kevin (reply attached below)

I have the same camera/lens combo. And I had the same problem. I sent the lens back to Sigma and asked that they fix, not replace the lens. Total time from mailing it Priority mail until I got it back was 1 week. It works fine now. It's a known problem with that combo, I don't know why Sigma hasn't corrected it in the manufacturing stage rather than mess with the returns.
Since the return, it has been a great lens.

[RicardoB]

I've been fortunate, apparently. No problems with the Sigma 24-70/2.8 Aspherical EX DG on my 20D. Great lens.

Rich

[kcrouth]

Originally Posted by RicardoB

I've been fortunate, apparently. No problems with the Sigma 24-70/2.8 Aspherical EX DG on my 20D. Great lens.

Rich

I sent mine off to Sigma last week. From what I've heard, it
will perfect after they do their magic to it.

kevin

[kcrouth]

Unfortunately, my lenses trip to Sigma was in vain. They "adjusted the sensor" which did not eliminate the problem I'm having with the 20D locking up, requiring the camera battery to be removed, or the lense to be removed and reinstalled. I called them again, and they said that if "adjusting the sensor" doesn't fix it then I'd have to send it back to them a 2nd time to get the "circuit board replaced", which I assume is re-chipping which is what I wanted to begin with. They WILL however pay shipping both directions, so that is good.

They also said that if the "circuit board" doesn't fix the problem, then they will replace the lense with a newer one.

So my saga continues, and as of today, I still do not have a working 20D and Sigma 24-70mm lense combination.

kevin

Originally Posted by kcrouth

I sent mine off to Sigma last week. From what I've heard, it
will perfect after they do their magic to it.

kevin