RF ultra-wide angle lens for full-frame cameras – especially suited to a mirrorless design, this lens is compact, wellbalanced and smaller than previous digital SLR ultra-wide lens designs. Incredible 10-20mm coverage for stills and video with full-frame EOS R series cameras. Excellent image quality: highlights include 1 super UD lens, 3 UD lenses, 3 aspheric lenses with Subwavelength structure coating (SWC) and Air Sphere Coating (ASC) to reduce ghosting. Minimum focus distance of approx. 9.8 in./0.25m with a maximum magnification of 0.12x. Canon leadscrew type STM (stepping motor) focus drive, especially suited for smooth, quiet video AF operation.