The *best* travel lens for cropped sensors

Author's Rating:

Pros: sharpness, contrast, focus, contra-light performance, build

Cons: sometimes highly distorted people, but no other serious con

The Bottom Line: 
Fantastic, now I almost ignore the standard 18-50 mm range.

Author's Review
Right from the purchase it has become my top lens - I carried it on my travels to Rome and Amsterdam and having the ultra-wide focal length paid off. Most of the photos in the following galleries was made with this lens:
http://www.pastel.cz/v/Photography/2008-09 Rome/
http://www.pastel.cz/v/Photography/2008-08 Amsterdam/

The lens is probably as close to perfection as possible: It's sharp and contrasty and doesn't matter if the sun is shining directly into the lens or not. In fact it is often hard to avoid it as the angle of view is huge. As with other lenses, Canon doesn't ship the lens hood and you have to buy it separately. This is not a disadvantage with this lens - you don't need any hood!

The USM autofocus works perfectly, though with wide-angle lens you have large depth of field and the precise focussing is not as necessary as with the telephoto lenses.

There are only two disadvantages: The focal length stops at 22 mm, which is not great, but then again - the lens wouldn't perform so well it it covered large focal range.

The second disadvantage is that people photographed with the 10 mm tend to be distorted if they are not in the center. This is due to the rectilinear nature of the lens, so it's not a thing that can be fixed with a new version of this lens, but you have to take it as a fact and deal with it (or use some software to partly fix this problem).

Last words: Almost perfect lens, you won't regret having it.