Canon EF-L USM 4,0/17-40

The Canon EF-L 17-40mm USM is a lightweight, ultra wide angle Canon EF zoom lens. It is especially well suited for use with digital EOS SLR cameras with a focal length conversion factor higher than 1.
Super Spectra Coating on the lens elements ensures excellent colour balance and minimises ghosting and flare. To provide superb image quality over a 17-40mm zoom range the lens uses three aspheric elements of two different types, while Super UD (Ultra-low Dispersion) glass is used to prevent the chromatic aberrations that often can degrade the subject edge clarity.