Auto Focus Canon VS Sigma 70-200 f/2.8

Anyone experienced with the auto focus on any of these models? I am very unhappy with the speed of the autofocus on my Sigma. I picked it up as a step up towards saving for the Canon f/2.8 IS, but the AF is proving to be a pain.

What body?

Shooting on my 20D

other lenses that focus as fast as Ive ever needed:

50mm f/1.8
10-22 f/3.5
28-135 f/3.5
75-300 f/4

so the Sigma is my first lens in this class.

css7493 wrote in post #11289710
Shooting on my 20D

other lenses that focus as fast as Ive ever needed:

50mm f/1.8
10-22 f/3.5
28-135 f/3.5
75-300 f/4

so the Sigma is my first lens in this class.

The Sigma should smoke all those in the AF speed .

I wish it did, I use that with my 10-22 about 99% of the time.

Hopefully it is the body, I hope to upgrade my 2x20ds to a 5d ii and 40d soon . . .

Do you have access to another body where you could test it? My Sigma 70-200 focuses just as fast or faster than my Canon USM lenses and I've been extremely happy with it. If you don't need IS there's really not much to be gained between the Sigma and the non-IS Canon. Back to your problem though, if it still focuses slowly on another body you may need to have Sigma take a look at it because it should beat all those other lenses you listed. Either way contacting Sigma couldn't hurt

I used to have a very nice Sigma 70-200 2.8 HSM EX DG and it's was a very nice lens. Sharp, but got sharper around below the 160mm point wide open. Or 200mm at f4. It also got sharper the closer to the infinity focus point. All in all it was a very nice lens. My biggest gripe about it was the focus accuracy. It was fast but sometimes missed the target. I'd often double pump the 1st pressure AF to make sure I was getting a consistent focus.

Thanks for the input. I need to put some more thought into what the issue is, on second thought it seems it could be accuracy which is making me think it is slow. Ala: slow to get what I want.