Canon 17-40mm f/4L EF Ultra Wide Angle
- Focus Adjustment - Inner focusing system with USM
- Closest Focusing Distance - 0.28m / 0.9 foot
- Zoom System - Rotating Type
- Filter Size - 77mm
- Maximum Diameter x Length, Weight - 3.3 x 3.8, 1.1 pounds
A new and affordable L-series ultra-wide-angle zoom lens that's ideal for both film and digital SLRs. Superior optics are assured by the use of three aspherical lens elements, in addition to a Super UD (Ultra-low Dispersion) glass element. Optical coatings are optimized for use with digital cameras. This lens focuses as close as 11 inches (0.28m), and offers both Canon's full-time manual focus and a powerful ring-type USM for fast and silent AF. It has a constant f/4 maximum aperture, and offers the choice of screw-in 77mm filters or a holder in the rear of the lens for up to three gel filters. Finally, it offers weather-resistant construction similar to other high-end L-series lenses. Lens Construction 12 elements in 9 group. Diagonal Angle of View 104° - 57° 30 feet.