Summary: I purchased this as a more affordable alternative to Canon's 16-35L, which I rent often. After using it for a week, I decided to return it. I really wanted to love this lens, but it's just not anywhere close to the 16-35L in terms of image quality. For my needs, this lens isn't sharp enough, despite the reviews I read, and creates too much distortion.
Excerpt: Awesome wide angle for my 5D mk ii. Most people think it's a fisheye because it can sometimes have that effect but otherwise photos are very clear and make people look great. It focuses quickly most of the time. The only downside is the heavy weight.
Pros: Durable, Easily Interchangeable, Strong Construction
Summary: I am very happy with this lens on my Nikon full frame D600. The images are tack sharp even at f2.8. Only little complaint is the flare depending on the angle of lights, but that is to be expected from such a wide angle lens.
Excerpt: I have been a Canon "purest" since the mid 70's and anything other than Canon was not the quality I wanted. However, after reading multiple reviews on the Tokina AT-X 16-28mm f/2.8 vs. the Canon 16-35mm f/2.8, I thought I would give the Tokina a shot. First off, the Tokina is half the cost of the Canon. Yeah I know, the "L" series Canon glass is the best of the best. I have to agree.
Pros: Easily Interchangeable, Fast / accurate auto-focus, Price
Excerpt: FYI - I am rating it 5 stars based on its price, not because it is flawless. Although I don't like to rate "value", because it is different for everyone, my rating is reflective of price.This is a solid, well-built piece of glass. It is heavier than my Tamron 24-70 (with vibration reduction). For me, ultra-wide lenses only have to do one thing well, and that is take a sharp picture.
Pros: Fast / accurate auto-focus, Low-vignette, Rugged, Sharp, Strong Construction
Summary: I had the Nikon 14-24mm 2.8. Unfortunately, it was stolen and at the time I didn't have insurance on it. I looked at different options and found the Tokina 16-28mm by chance. It seemed like the perfect solution. After seeing it in person, it won me over. The build quality is exceptional, it feels almost as solid as my 14-24mm did.
Summary: I did find the lens to be sharp, but the flare made it unusable for me. I did one real estate shoot with it and found some of the shots to be unusable due to the flare from window light, it was sunny outside, but the window was not facing the sun so the amount of flare really surprised me.. I'm returning it.