Sigma 50-100mm 1.8 DC HSM Art is a premium mid telephoto zoom lens designed for APS-C sized sensors. Part of the Sigma Global Vision Art Line, the 50-100mm 1.8 is the second lens to feature a 1.8 aperture all the way through it focal length and factoring in the APS-C increase, the lens covers a highly useful range of 75-150mm. An enhanced and slimmer Hyper Sonic Motor (HSM) provide fast and accur...