Large F/2.8 maximum aperture for bright viewfinder image and pinpoint focusing even in dim light. Ultra-wide 94 degree picture coverage with edge-to-edge sharpness. Tremendous depth-of-field enables no-focus quick shooting and action photography. Close-Range-Correction (CRC) System assures center-to-edge sharpness even at close range. Minimum focus distance .85ft. Retrofocus design means virtually no corner light fall-off even when wide open. Uses optional HK-14 slip-on type hood. Can be used with either the TC-14A or TC-201 Teleconverter.