This is the greatest lens I have ever used. It is wider than my 18-55mm EF-S kit lens that I got when I first bought my camera (30D), and not to mention the fact that kit lens was a f3.5-5.6 and this is a f2.8. I use it just about everyday on my general news assignments and has allowed me make better photos in low light. I can not wait for football season.

This lens is wonderful for landscape and wedding photography! It adds a very creative perspective to wedding and portrait photography that many people overlook. It's very sharp and focuses extremely quick. As with all 'L' lenses, the build quality is superb and I can expect this to last a very long time. Just add an 82mm UV filter to make this lens completely weather-sealed! I say this lens can be somewhat difficult to twist on because the majority of the body is filled with focusing rings! Lens hood is HUGE and makes it difficult to store in some bags. It doesn't stash away with ease.

I use this lens quite extensively for my personal photography . It's a great reportage lens !

Profession shooter. Couldn't live without it!

Great lens for landscapes, weddings, architecture and everything in between. I just upgraded from the 17-40 and well worth it. The focusing in low light at weddings without flash is much faster of course and the 16mm for architecture saves me from having to buy the 14mm and does suprisingly well with lens flare. Also for a 2.8 it is suprisingly light weight and like everybody else buying new 82mm filters is not fun. I'll mention it anyways this lens is very sharp.

I have 70-200L and debated a long time between this 16-35L and the 24-70L. Very pleased with the 16-35L and found the wider angle much more useful than I ever expected. I have not found that I need to fill the gap between the 35 and 70 at all. Great lens, very sharp, a little heavy for a wide angle but worth it for this quality of lens.

the field of view is phenominal! with minimal distortion. We use this to create a really kewl different look for our senior portraits and wedding photography!

I do pictures for my photo album. This lens has very quick autofocus. Easy is perfect. I'm with this product very satisfied.

This lens was an upgrade from an older sigma of the same focal length. The canon has the ability to lift the image, likely because it presents high contrast and sharp results. I use it for wide shots of people, where end to end performance is important.

Just got my EF 1635 f/2.8L II last week took it out for some shots on my 5D. I was very impressed with the results (I have read mixed reviews on this lens) my copy is very much acceptably sharp even wide open on the corners!!! awesome contrast & resolution very sharp in the center wide open. Needless to say I am very happy with this lens, worth every penny!!!