Fisheye photography, and this lens provides limitless creative potential, I did not realize it until I actually used it. I saved $$ and thought about it for a few months, then pulled the trigger. I'm glad I did, the lens produces great pictures, very sharp. Great built, weather sealed, solid and smooth feel of the focus and zoom rings. The lens is actually smaller than it looks on the website, not heavy, looks and feels great, but best of all, it produces some really cool shots! Especially using a full frame camera, I use a 5Dmk3 and the shots I get in low light outside are just stunning.