[updatemore]

I want to buy a 超廣角鏡, but don't know which one is better (show below)

Tokina AT-X 124 AF PRO DX AF 12-24mm f/4

Sigma 10-20mm F4-5.6 EX DC HSM

Canon EF-S 10-22mm f/3.5-4.5 USM

[Teddy So]

Canon EF-S 10-22mm f/3.5-4.5 USM

[hungjacky]

I am using Canon 10-22, 唔錯

[wesleytzwong]

either tokina and canon is quite good.
i dont recommend sigma one

[ntwilliam]

If your budget allows, get the canon 10-22. I am using it and am very happy with it.

Tokina is better than Sigma but it is only 12mm, not wide enough.