There is a lot of negative reviews about this lens on the internet. The lens performs very well for what I use it for, namely landscape photography. I have tested this lens against the more expensive offerings from Canon (16-35) and the 17-40 performs very well at f/8 and beyond. If your primary use of the lens is for landscape photography I can stronly recommed this lens but if you are lookign to shoot wide open with this lens you will be better off with the 16-35.

noriravi

Manchester, CT

I am a "mom with a camera" amature photographer. I've been practicing and thinking about maybe taking photography further. I was recently doing a newborn photoshoot with my 50mm 1.8. The pictures were just not coming out well at all! I decided to change it out with the Canon 17-40mm. Until this point I had not played with my 17-40mm very much. The difference was amazing! It offered clean crisp pictures indoors in natural light. The range worked well in my small home studio set up. I also used this lens to photograph an indoor birthday party. The images were beautiful. I don't know what else I can say! I've since taken it outdoors to do a little landscape photography and it's consistently performed well. I am very pleased with this lens. It's lightweight and fits nicely in my camera bag, attached or not attached.

JediMomHeather

San Antonio, TX

This Canon 17-40mm Lens is one of the cheaper to afford 'L' lens Canon has. This lens features a constant aperture of f/4 across 17mm to 40mm which almost every other zoom lens cannot do. Most zoom lens f-stop will increase as you zoom out. In other words, the aperture will decrease as you zoom out. The constant f/4 of this lens is what makes this special. At 40mm lens you can still set your aperture to f/4, which is the aperture I like most to shoot portraits! If you have this lens on a full frame body the 17mm might be too wide. Vignetting will be visible (although that is fixable in processing programs). Another good point of this lens is that since its an 'L' lens the lens itself is weather sealed. All 'L' lenses are weather sealed. That means you can shoot photos in the rain! Or you can dip your camera slightly under water to get a good angled shot (Remember to check if your camera body is also weather sealed!). The Lens itself is kind of soft but this opinion might be biased because I am used to prime lenses.

bonaina

Irvine, CA