This is the Sigma 18-200mm f/3.5-6.3 II DC OS HSM lens:
Samples
Full-resolution photos at Impress, shot with a Canon 60D.
Resources
Official Sigma 18-200mm II page at Sigma Corporation (Japan).
Related
Sigma Lenses – Main page.
Canon Lenses – Main page.
Nikon Lenses – Main page.