Well-suited for wide-angle shots, this large-diameter wide-angle zoom lens ensures the delivery of bright and impeccable quality images even in dimly lit environments. Designed with two large-diameter double-surface aspheric GMo lenses, one ground aspheric lens, and two UD lenses is able to achieve high image quality from the center to the edge of the frame, befitting the L-series lenses. Distortion and chromatic aberration is also greatly reduced, especially in the wide end. The coating of Subwavelength Structure Coating (SWC) & Air Sphere Coating (ASC) also suppresses flaring and ghosting. Built to help photographers withstand challenging conditions, the dust-proof and drip-proof structure has been applied to the key areas of the lens.