Slow to focus 17-40L?

I was just wondering if its normal for a 17-40L to be a bit slow to focus. It hunts around a lot, especially in low light. I know this is normal except it does it more than any of my other lenses. Is this normal, how do your 17-40's compare?

In low light, definitely, but that's not your lens, its your camera. The 10d has never been an allstar at focusing in low-light. If you put an expernal flash like the 580ex on it there is an infrared beam that assists in low-light focusing. Most of the ex-series flashes do this.

I find the 17-40 to be a very fast focuser in good light, even on my 10d. It should be faster than your 70-200. My new 5d is much better in low light as I would assume the 20-30d are and any of the 1 series bodies.

I've not experience of the lens on any other camera than the 350D, but certainly with that body, I've not found the lens to be slow to focus.

Super fast on 1dmk2.

Mine's OK on the 20D and 5D unless there is very little contrast in the subject for it to latch on to in very low light situations... From what I can remember I didn't have any problems when I had the 10D either...

Thanks for the info, I think I need to do further testing to see if there really is a problem. At least now I know it should be fast.