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

Canon’s ultrawide zoom for crop frame cameras (T1i, 7D, etc…) only. On these cameras the range is very similar to the 16-35 on a full frame camera. The lens is very sharp. It has amazingly little distortion and is surprisingly resistant to lens flare for such a wide zoom.

Only Works With: Crop sensor cameras (T1i, 7D, etc…)

Does Not Include: Lens hood (all Canon non-L lenses do not come with hoods).

Roger’s Take: Comparing the ultra-wide, crop-sensor camera lenses is an extremely difficult task, so I’ll put the summary first: they all deliver excellent image quality and you can’t go wrong with any of them. To my ‘just taking pictures’ assessment they are all excellent. There are some differences though, so I’ll try to point those out so you have a better chance at choosing the one that’s best for you.
The Canon 10-22 is arguably the most flare resistant, the smallest and lightest when that’s important, has low distortion. Its also the most expensive and vignettes a bit. I like it a lot, though, and often find myself preferring it because of its small size.
The Tokina 11-16 f2.8 gives you the widest aperture if you’ll be working in low light (with ultra wides, depth of field is rarely an important point), but its a bit soft at f2.8, so the aperture advantage isn’t huge (I usually shoot it at f3.5 if I can to get it sharper). It has very little vignetting and distortion, probably the least of the group. Unfortunately it does show quite a bit of chromatic aberration at times. Overall it may be the best image quality of the group.
The Tokina 12-24 f4 PRO is built like a sturdy tank (and therefore a bit heavier) and does tend to give low contrast images when shot into the sun but is quite sharp otherwise. This the one I’d take if conditions were rough: I pity the rock this bad boy falls on. Poor rock.
The Sigma 10-20 f3.5 has a bit more distortion than the others but delivers very nice images and is also built much better than the Canon 10-22. It does everything well.

But like I said above: they’re all excellent. We hardly ever get anything but happy comments about any of them.

High Risk Lens: The Canon 10-22 f3.5-4.5 lens has a SLIGHTLY higher failure rate than most lenses in our lineup.

• How high? The 10-22 has a problem rate of 1.00% of rentals, despite being checked out thoroughly before it leaves us.
• Why? Design flaw – weakness in the mid barrel.
• What’s the point? We’re letting you know on the front end make sure you order this lens in time to check it out before you leave for vacation or schedule your big shoot. We can send a replacement if it has a problem, but we can’t send a replacement Friday night to get to you you Saturday morning.
• Type of problem: The barrel separates just below the zoom ring, causing the zoom to become stiff. While this is rare, it seems to sometimes occur during shipping.
  Note: The 10-22 just barely makes our ‘high risk’ designation. It’s a great lens, but has a bit of inherent weakness between the zoom ring and the barrel.