Just another post for those who is deciding between these two. I have been using the Canon 10-22 for about a month now. Today, I got my hand on a Sigma 10-20. I am selling this lens for a friend. Here is a few initial impression and comparison:
1. The Sigms is NOT internal zoom, which means its length extend when zoom toward 20mm, but not much, only about 5mm.
2. The Sigma EX built & finish is very very exellent. I have owned 3 Canon L: 17-40, 24-105, 70-200F4L. I would say the EX built & finish is as good, if not better than 24-105L. The 17-40 and 70-200 being internal zoom feel a little more solid, especially the 70-200L with metal casing. Zoom ring and focus ring smoothness is on par with any L. Overall built is way better than Canon 10-22 or any Canon non-L.
3. EX comes with hood, but hood design is not as good as Canon 10-22. Mainly because it is too narrow, it is very difficult to take off or put on lens cap with hood on. I have always complain the 10-22 hood is too wide, but now I understand it is for a reason. The EX hood also doesn't go in as smooth as Canon hood (not a big deal but noticeable differences)
4. Lens caps. Sigma definitely skim here. Both caps are made of low quality platics. Canon caps are way better here.
5. HSM AF is louder than Canon USM, also feels slower. Canon USM feels more refined and snap into focus more effortless. As for actual AF performance, it is about the same tho. I think being ultra wide, AF can never be too bad.
6. Front element of the EX is very small compare to Canon. This makes me wonder why Sigma need to make it 77mm thread. It looks to me it can be made into 58mm or at most 67mm
7. The EX being 2mm shorter at the long end should NOT be a concern for anyone choosing between this two lens. I found a little crop can easily make a 20mm shot looks like a 22mm shot..
8. Looking through the view finder, the EX gives a different look then the Canon. EX seems to be a little darker, warmer and more "grainy".
9. IQ. So far, I can say the EX is very good. It is definitely compatiable to Canon at center. The edges also seem compatible, but I think I am not used to shooting UWA, even with Canon, the edges don't seems too sharp to me. Maybe I am so used to the 17-55IS sharpness.
10. Sigma's package is a lot better than Canon. The box is much nicer made. It comes with a very nice lens case. And a 4 year warranty card.
So far, this is my 1 month Canon experience vs 1 day Sigma impression.
The Sigma is such a bang for the buck lens. It goes for about $445 new (buydig free shipping). I got my Canon for $609 (BH deal) + $35 Hood (Ebay) + shipping. So this makes Canon exactly $200 more than the Sigma.
My suggestion to those who is choosing between these tow is if money if absoultely not issue, go Canon, I still believe it deliver slightly better optic perforamnce. If you want to save $200 and get a compatible (very comptable) lens, then Sigma is the one to get. If I were to do it again, I would probably go with Sigma too.
eel


