> I'm looking for a relatively fast zoom lens for my 10D, trying to decide
> between the Canon EF 70-200 f4L and the Sigma 70-200 f2.8 EX.

> I've found both lenses at similar prices (Canon slightly more expensive),
> and on paper it seems the Sigma is the way to go (as it gives you a couple
> of f-stops more) but wanted to hear from people who've used these lenses and
> what they think of them.