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

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

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

• 17-40mm ultra-wide-angle zoom lens with f/4 maximum aperture for Canon SLR cameras
• 3 aspherical lens elements and super UD glass element create superior optics in all conditions
• Powerful ring-type ultra-sonic monitor (USM) produces fast and silent autofocusing
• Focuses as close as 11 inches; supports screw-in 77mm filters or up to 3 gel filters
• Weather-resistant construction; measures 3.3 inches in diameter; 1-year warranty

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 with digital cameras. Boasting weather-resistant construction similar to other high-end L-series cameras, the lens carries a one-year warranty.

• Focal length: 17-40mm
• Maximum aperture: 1:4
• Lens construction: 12 elements in 9 groups
• Diagonal angle of view: 104 to 57 degrees (at 30 feet)
• Focus adjustment: Inner focusing system with USM
• Closest focusing distance: 0.9 feet
• Zoom system: Rotating type
• Filter size: 77mm
• Dimensions: 3.3 inches in diameter, 3.8 inches long
• Weight: 1.1 pounds