Canon 70-200 f4 vs Sigma 70-200 f2.8

[StraussHouse]

So I'm pretty new to sports photography and just starting out. I want a good lens to shoot baseball pictures that can capture the action without any blur. I am using a digital Rebel Xt. So what lens should I go with? I've heard nothing but good things about both. I guess the obvious answer is the Sigma but what do you guys think? (Guys meaning everyone, females included ;) )

[SmartWombat]

I've not tried those, but I tried the Sigma 80-400 and the Canon 100-400
For me the Canon was better - far more expensive. but better.
I'd heard good and bad about both the 80-400 and 100-400. What clinched it for me was image quality, image stabilisation performance, and flare at night on racing car headlights.
For pretty static shots (no panning) and daytime use the Sigma was good enough.

Personally, I'd recommend Canon not Sigma.
I was lucky enough to be able to take the Sigma back and exchange it for a Canon - plus paying a few hundred more of course!

But if cost is an issue, then I'd say probably the Sigma is your only realistic option.

My basic premise is buy the best lens you can afford.
By saving up and buying "L" lenses then I hope I only have ot buy once - not buy cheap and buy the lens I really wanted later.

The exception is the EF-S 10-22 which I expected not to use a lot, and I was willing to take a chance on that, since it will eb many years before I can afford a 1DII body

[Arctirus]

My 70-200 F4 L is slow to focus.

[Lionheart]

So I'm pretty new to sports photography and just starting out. I want a good lens to shoot baseball pictures that can capture the action without any blur. I am using a digital Rebel Xt. So what lens should I go with? I've heard nothing but good things about both. I guess the obvious answer is the Sigma but what do you guys think? (Guys meaning everyone, females included ;) )

Why not the Canon EF 70-200 f2.8L non-IS? It's still available, it's a great price for the image quality (now there's an understatement) . I've had both IS and non-IS versions, and I feel like the non-IS version was quicker focusing than the newer IS version. The f4 70-200 will probably be a tad slower focusing just because of the lower light available for focusing, and if you're shooting on a 1.6 crop sensor, then your viewfinder is a heck of a lot darker than it is on my 1D mkII (I know that the 10D and D60/30 viewfinders are considerably darker than my 1D/mk I and II view finder), which may have an effect on the camera's ability to focus both automatically and manually. Just a suggestion-I've never been keen on Sigma zooms on EOS cameras, but I'm very enamored of Canon "L" glass.

[Liz]

Why not the Canon EF 70-200 f2.8L non-IS? It's still available, it's a great price for the image quality (now there's an understatement) .

I agree 100%. This lens has a great reputation! Fine reviews and many sports photographers rave about it. I don't have experience with it, but I've seen quite a few awesome shots with it. I think the 70-200/f4L is a great lens, but for sports, the f4 is a bit slow.

Liz