Canon Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for Canon SLR Cameras

Product Description From the Manufacturer: Broaden your perspective with the Canon EF 17-40mm ultra-wide-angle zoom lens. Ideal for both film and digital SLR cameras, the lens offers three aspherical lens elements in addition to a Super UD (ultra-low dispersion) glass element, creating superior optics in all conditions. From the Manufacturer Broaden your perspective with the Canon EF 17-40mm ultra-wide-angle zoom lens. Ideal for both film and digital SLR cameras, the lens offers three aspherical lens elements in addition to a Super UD (ultra-low dispersion) glass element, creating superior optics in all conditions. In addition, the lens focuses as close as 11 inches (0.28mm), and offers both Canon's full-time manual focus and a powerful ring-type ultra-sonic monitor (USM) that produces fast and silent autofocus. Other features include a constant f/4 maximum aperture, the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters, and optical coatings optimized for use w...