I was recently shooting some of the Olympic landmarks around town and was left wanting a wider-angle lens, so I inquired with my local pro shop that rents lenses who had a Sigma 10-20. I went out one evening and was surprised how versatile a lens like this really was... 10mm lets you get very close to large objects yet incorporate tons of background 14mm still covers an absurd amount of area I decided that I need to extend my range on the wide end and started looking into the alternatives. I read numerous reviews that all praised the Canon EFS 10-22mm f3.5-4.5 and the Tokina 11-16mm f2.8. The Sigma was also considered a decent contender and my experience with it was nothing less than very satisfying. However, I was a bit partial to the Canon for the focal range and the sharpness and flare resistance lauded by many reviewers. Since I couldn't imagine shooting at wide apertures with this lens, the appeal of the Tokina's max aperture of f2.8 held little value. There's also the emotional attachment (irrational or otherwise) to a Canon branded lens and the difficulty in even finding the Tokina that narrowed it down to Canon's EFS 10-22mm. When a 6 month old sample came available on CL for a good price, I jumped on it. The addition of this lens really complements my 17-55 and 70-300 providing me with a full array of focal lengths from 10-300mm or 16-480mm equivalent on my crop-body DSLR. The Canon 10-22 is constructed almost identically to the 17-55mm f2.8. It's a bit smaller but a LOT lighter. It uses the same 77mm filter size which may be handy for those who use filters. It lacks IS, which is probably not a bad thing, except that it will require more tripod use. It's interesting to note that the field-of-view of the average human eye is about 160-degrees... amazing really. The fact that this lens has a 107-degree field -of-view at 10mm is remarkable. It comes as close as possible to covering what you can actually see from where you stand. And in my observation, I would say it covers what I normally consider my active field of view, that is, not including my peripheral vision. Here's a perfect example, this image captures my office perfectly as you enter... My office at 10mm: just as it would appear as you walk into the room It seems ideal for capturing interior spaces. It's also great for capturing very large nearby objects in full... and while I've read this on numerous sites, it really is best to get closer to your subject with this lens (as with the Inukshuk pictured at the top of this post). Great for capturing the full extent of large subjects with someone nearby for scale Of course, with such a wide field of view, you really need to take care with composure. Watch where your shadow is, your tripod legs, and what may not be visible in your cursed (less than 100%) viewfinder... is it really that difficult or expensive to include a full 100% viewfinder in a budget DSLR? Great for city architecture - this one taken from directly under the cherry trees The bottom line is that I would highly recommend a wide angle zoom to anyone who's already got their other top-priority focal lengths covered, this can open up a whole new world of photographic opportunities.