Compatible with full-frame, 35 mm image sensors, HD PENTAX-D FA 24-70 mm f/2.8 ED SDM WR Lens features large f/2.8 constant maximum aperture and 24–70 mm focal-length, minimizing need for tripod in low-light conditions. By incorporating 3 Extra-low Dispersion optical elements and 4 aspherical optical elements, K-mount lens assures sufficient light levels even at edges of image field, and compensates for aberrations. Built-in Supersonic Direct-drive Motor provides high-speed autofocus.