Tamron AF 10-24mm f/3.5-4.5 SP Di II LD Aspherical Lens for Canon Digital SLR Cameras

The world's first 2.4X zoom with an equivalent 16-37mm (when converted to full frame)The best magnification ratio in this class of 1:51Extremely compact and lightFlower-shaped Lens Hood and Case Included77mm Filter size
Product Description The ultimate extended-range, ultra-wide-angle zoom lens! Wider and longer than others in its class, this compact, lightweight, high-performance lens for DSLRs with APS-C size sensors provides 35mm equivalent coverage from 16mm ultra-wide to 37mm

Source: Digital Camera and Video Store...