Details: Lens not zoomable Digitally-optimized, circular fisheye auto-focus lens Produces circular images with an angle of view of 180-degrees when attached to a full-frame digital or 35mm film SLR camera Maximum aperture of F3.5, a minimum focusing distance of 5.5 inches, and a maximum magnification of 4.6x Super multi-layer lens coating reduces flare and ghosting Gelatin filter holder at the rear