Sigma 10-20... details please

Well I started really lookin into UWA's as the start to my high end lens collection. At first I settled on the sigma 10-20, then changed to the tokina 12-24. Now I am rethinking my reasoning on the Tokina (thinking ahead to FF? better build?) but wait, I don't ever want to go FF, I want to shoot sports. So what was I thinking? But I do want to go 1D.

So, does the Sigma have an "efs" mount, or will it still be compatable with the 1dmII?
Also, everyone gets into detail about the tokina and canon, their exact flaws and such, but are there any problems with CA and what not with the sigma? Also is the HSM much better than... not?

I really think I want the Sigma, but only if I can keep it for a long time.

Thanks for any help

If you upgrade to a 1-series body, you are still going to keep your 20D as a backup and use your 10-20 on it.

Both the Sigma and Tokina will physically mount to a 5D or 1D series. You'll get vignetting but they will "work." My simple answer to this issue is if you're going to go wide, then go 10mm wide. But the Tokina is a nice 12mm lens.

The Sigma 10-20mm will supposedly FIT on any EF mount, but it is made for smaller sensors like the Rebel XT and 20D. The corners will be vignetted to black on a full frame camera.

Sigma's lens has average CA, pretty minor distortion (barrel, pincushion), some vignetting, handles flare pretty well, and has pretty good center sharpness wide open but has to be stopped down to improve the corners. I was told that because it's ultra-wide, you have to expect certain flaws.

I had a decentering issue with my first one, but the replacement seems okay.

Had the toke, have the sig. Both are nice lenses. Can't go wrong with either one.
Only Canon uses EF-S mount, rest are EF mounts, althogh the rear element is smaller, they work with 1Ds/1D series. Yup you do get light falloff with these till you crank the focal length back to about 17 or so.

The hood and the toughness of the toke is nicer in my view along with it's constant f4 and it's cooler color cast.
The 12mm vs 10mm isn't as nice though. The toke does have more CA as well.

The sig's hood is so tight fitting to the lens that you cannot rotate the CPL with the hood on, which is a pain. The orange color cast is a bit annoying now, and I don't think it's as sharp as the toke.
The price is good, it comes with a nice bag, the HSM AF is nice as well.

I really don't think there is a bad choice between these two. Just gotta go with the one you like more.

I've tried both, and I own the Tokina. Both are outstanding lenses. The Sigma is very well built, and is very sharp, with minimal CA. It has very strong distortions at the wide end, though, and it's not as long (I find myself using the extra 4mm more than I wish I had the extra 2 at the wide end.) While I shoot at 12mm a LOT, it's always wide enough for me. Only about 2 shots have I said "I wish I had 10mm," though there are countless shots where 24mm was very nice to have.

The Tokina is extremely well built (L-quality for sure..it's a pleasure to use), very sharp, with minimal distortions, though it exhibits a lot of CA in high contrast areas. I can fix the CA very easily with the PTLens filter in photoshop, so it's not a big deal.

Both are excellent. I would imagine you would be happy with either. I love my Tokina, and you'd have to pry it from my cold dead hands. I'd probably feel the same way about the Sigma if I'd gone that route, though.

the sigma and tokina will both mount to any EF mount (granted you bought the EF mount version of course ) but with a full frame camera, you'll get pretty severe light fall off at the corners.

there are 3 solutions to this:

1) buy the canon EF-S 10-22, sigma 10-20, or tokina 12-24 for your crop body and if you go full frame in the future, these lenses still have great resale value. sell and buy yourself a 16-35L or 17-40L which would give you the equivalent focal length of the 10mm on a crop body.

2) buy the sigma 12-24mm f/4.5-5.6 EX HSM. it's the widest UWA zoom totally compatible with full frame sensors on the market.

3) buy the sigma 10-20mm f/4-5.6 EX HSM DC and mount it to your (future) 1DII/N with the 1.3 crop factor. the heavy vignetting disappears at a mere 11mm so there's still plenty of use to be had with it. also, on a full frame, light fall off at the corners seams to disappear at 14mm as opposed to the tokina's 17mm.