I look forward to lend me a EOS 5D Mark II, for example, to be able to try this lens on a full-frame housing and the fully exploited. I appreciate that this objective is a zoom, not a fixed focal length, and makes it possible to have both a fish-eye circular and full frame fisheye a single goal (provided, therefore, the use a full-frame sensor). However, even with an APS-C sensor, the angle of view (180 ° horizontal and vertical) and distortion of perspective are impressive, and allow extreme images. Just do not abuse it, otherwise you will quickly tire people that you show your photos.
Last thing: attention to your feet, which were quick to appear in the photo, even if you do not shoe size 47 and even your left hand if you choose to focus manually. For the rest, the Canon quality is at the rendezvous.