The Sigma 30mm f/1.4 DC HSM A has been labeled by Sigma as the go-to lens for the artistic photographer. Top features include: bright f/1.4 aperture, angle of view imitating human vision, minimum focusing distance of 11.8" and 1:6.8 max magnification ratio, and optimized autofocus for smoother focusing. The Signa 30mm designed for APS-C DSLRs has the latest lens technology with motor driven ultrasonic waves to deliver quiet, high speed autofocus. USB Dock option is available for firmware updates and parameter adjustments.