I'm a professional photographer & use the Canon L Series lenses regularly, & while this lens is not a regular feature in my camera bag, I've used it enough to give it a pretty good review I think. For starters this is an extreme wide angle lens, it is an 8-15mm zoom lens, with a maximum aperture of f4, which at that focal length acts as a fish eye lens. If you're unsure what the term 'fish eye' means it is basically a distorted curved image, the focal length is so short that it curves that would otherwise be straight lines of perspective (tall buildings for example, will appear curved in the frame). It's a type of image which has often been used on ...  Read the complete review