I actually just bought my camera setup, I had to get the 1.8/f canon actually because the 1.4/f versions both pushed the price way too high for me right now.

I wonder if you zoomed in a bit, then would the corner be sharper?

Yes, of course because it would simply crop the very soft corners but then again at 20mm it is also very close to some of the much sharper lenses like the 24-70L so there is really no point. The Sigma is meant to be used at 10mm and for situations when you want to get as much as possible in your shots. I am afraid both you and me have to make do with what we have because a decent solution to that problem would cost over 4000 bucks i.e. Canon EOS 5D mk2 with either EF 16-35mm or Nikon 14-24

This post was edited by Futurama on Jul 16 2010 01:53pm

Aren't any other brands like Tameron or Tokina offering lenses similar to this?

Such as, Tameron's 11-18 and 10-24.

Ehh.. I'm afraid I'm never going to want a slower lens after I use the 1.8/f for so long. Even when I was just using the 1.7/f manual focus I still couldn't stand even 4/f on my other lens.

This post was edited by kratos on Jul 16 2010 02:28pm