Canon EF 17-40mm f/4.0L USM: Digital Photography Review
,Canon 17-40mm f/4 L USM EF Mount Lens {77} - With Case, Caps and Hood - EX+,Amazon.com : Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for SLR Cameras : Camera Lenses : Electronics,Canon EF 17-40mm f/4.0L USM: Digital Photography Review,Amazon.com : Canon EF 17-40mm f/4L USM Ultra Wide Angle Zoom Lens for SLR Cameras : Camera Lenses : Electronics