canon 2.8/16-35mm L

When mounted on a 1.6x crop "factor" digital SLR bodies the field of view of the excellent 16-35mm lens to the equivalent of a 26-56mm lens. Optical quality is superb, with excellent colour rendition and low distortion. Auto-focusing is very fast and silent. With a maximum aperture of f/2.8, this is a sizeable piece of glass. Canon have also released the less bulky 17-40mm f/4.0 (L) lens, which I understand compares favourably with this lens.
STOP PRESS: Canon 16-35mm f/2.8 L Mk II
Canon announced in February 2007 a new version of this lens (Canon 16-35mm f/2.8 L Mk II) with completely redesigned optics. They claim vastly improved edge sharpness. If you own a 1.6 crop factor camera body, this news may be of less interest to you, but for full frame users, this might be of considerable interest.
Sample Pictures (Click to enlarge)
At
35mm
Cefalu, Sicily
At
26mm
Temple at Segesta, Sicily
At
19mm
Abandoned Fiat, Roma
At
16mm (landscape)
Panorama from Erice, Sicily
At
16mm (interior)
Duomo di Monreale, Sicily