A new and reasonable L-series ultra-wide-angle optical lens that is ideal for each film and digital SLRs. Superior optics arassured by the utilization of 3 rounded lens components, additionally to a brilliant UD (Ultra-low Dispersion) glass part. Optical coatings ar optimized to be used with digital cameras. This lens focuses as shut as eleven inches (0.28m), and offers each Canon's full-time manual focus and a robust ring-type USM for quick and silent AF. it's a continuing f/4 most aperture, and offers the selection of screw-in 77mm filters or a holder within the rear of the lens for up to 3 gel filters. Finally, it offers weather-resistant construction like alternative high-end L-series lenses