It is a lens beautifully manufactured, but relatively heavy. The Canon EF 8-15mm f / 4,0 L USM is a versatile fisheye zoom allowing to choose between circular shooting or full format, and can be used on both a full-frame or APS-C camera. It produces images with a 180 ° diagonal viewing angle with all EOS Reflex cameras from full-frame to APS-C and circular fisheye images of 180 ° with full-frame EOS models.
It belongs to the high performance Canon L series and provides a very nice image quality. Concerning Canon, it is my choice, from all lens in the test, it is also the one I found the most versatile, very pleasant to use, enough to make owners of Nikon or Sony cameras jealous. I recommend it unreservedly despite its price. The Canon EOS 5D Mark III and Canon 8-15mm, this is a successful duo.