Built for cameras with APS-C sensors, Sigma's ultra-wide rectilinear zoom is one of the widest available. That gives you the equivalent of a 12-24mm lens with 121.2-degrees of viewing angle. Inside, there are FLD (low dispersion) elements to combat color aberration as well as one hybrid aspherical lens and two glass mold elements for correcting distortion. It uses a Hyper Sonic Motor for fast, quiet AF and focuses down to 24cm (about 9.4-inches). No price or release date are yet available.