Hey everyone! I'm running into a little problem. I haven't been paying much attention my last couple of shoots because it hasn't been an issue, but after shooting a low light reception over the weekend I realized that the red AF assist beam from my 580EX II is not working with my 30D. I put it on a Rebel XT and the AF beam emits. Is there possibly a setting other than custom function #5 on my 30D, which is set to 0:emits that could be causing this?? Thanks!!

check your flash manual. i think you may have to turn it off in the flash's function menu.

Well, the problem is that its not working. I found the custom function inside the flash settings. It is set to emit the AF Assist beam.

Was it working before at all?

Another thing to watch is your AF mode. The AF-Assist light WON'T fire if your camera is in AI-SERVO mode, but it does in ONE-SHOT mode.

Shan

AI-Servo it is! Im an idiot! Thanks!

Nah, not an idiot. It took me weeks to even realize that it wasn't being used. It's not well documented.

Glad I could help though!

Shan

There also is an issue with sigma lenses and the AF assist on the 30d. HTH!

Really? I've never had any issues with the Sigma lenses and AF assist (we have a 40D, several 20Ds, and the 1D though - no 30D).

What issues?

Shan

I believe it also won't emit if a non-center focus point is selected.

-TM

nope - that works.

I know the Sigmas FLASHES won't cover all 45 AF points on the 1 series, but I've never heard any issues of sigma lenses having AF assist issues....

Hi Shan!

I'm sorry I didn't see your post right away.

My 30D and my Sigma 18-50 2.8 didn't focus properly when using the AF assist beam (but not the flash) on both my Canon 580 and Sigma flash.

That was the only case that it didn't function properly. Sigma advised me to send it in for rechipping. As a stop gap, I used the custom function on the camera to turn off the auto assist beam. Unfortunately the lens met an untimely death when it hit the pavement, so I didn't get to find out if the rechipping worked.