Nikon is clearly the best, perfect on a Canon body
L. Schrader, Amazon
19 October 2013
Summary: This lens can mount perfectly as a manual lens on a Canon body, remember manual? It's how those photos in most galleries were done. I have used most WA lenses, the Tokina 11-16 is boat anchor heavy, and has bad purple flare, and the difference in weight, flare and sharpness, no way make up for the slight 1/2 stop gain.
Summary: I ordered this lens to replace another wide angle. It was highly recommended by user groups on Flickr and I had some previous experience with it at a lens rental site. I'm mainly using it for street photography, portraits and landscapes.
Dramatic results for landscapes and a useful range for architectural exteriors and interiors.
John in Los Angeles, Amazon
20 August 2013
Summary: Extending the zoom range to 24mm (36mm full-frame equivalent) reduces the need for lens changing, and this is the biggest plus for me as a walk-around lens for architectural exteriors and interiors. This is an extreme wide-angle with some softness at the edges. It also has chromatic aberration and some distortion, but that can be readily dealt with in-camera or in post-processing.
Summary: Recently bought the Nikon 5100 with the lens that was part of the package. As a realtor, this lens was not wide enough. I do like this new one, it is much wider. There is a learning curve for me as previously only had point & shoot cameras.