The Canon EF 8-15mm f/4L Fisheye USM Lens is the worlds first fisheye zoom lens that offers both Circular and Diagonal fisheye effects. With just one lens, it allows EOS full-frame DSLR cameras to achieve both 180-degree Circular and Diagonal images perfectly. It also supports DSLR cameras with APS-H or APS-C sensors, ¡¥H¡¦ and ¡¥C¡¦ markings are provided on the lens to indicate the zoom position when the 180-degree Diagonal fisheye view can be achieved respectively.

This lens consists of 14 lens elements in 11 groups, including one Ultra-low Dispersion (UD) element and one high-precision glass-molded (GMo) aspherical lens to correct various kinds of aberrations. The inner surface of its front lens element is treated with SWC (Sub Wavelength Structure Coating) to minimize flare and ghosting common to wide angle lenses as a result.