Noted as one of the many standard zoom available to photographers. The Sigma 17-70mm offers a relatively long zoom range 4x ratio coupled with an impressive large maximum aperture at 17mm. The 17-70mm DC is specifically designed for the reduced image circle of today's APS-C DSLRs where the field of view is equal to 26-150mm (full format). The lens is equipped with Hypersonic Motor, Special-low Dispersion, and zoom lock. Optimized with tight controls, no wobbling and a mild Zen finish is great for everyday use.