Sigma 17-50mm f/2.8 EX DC OS HSM FLD Large Aperture Standard Zoom Lens for Canon Digital DSLR Camera Includes Bonus Xit Bounce Zoom Slave Flash Enhance Photos, Colors and Saturation, and More SIGMA AUTHORIZED DEALER With FULL Warranty INCLUDES BONUS Xit Bounce Zoom Slave Flash Enhance Photos, Colors and Saturation, Vivitar Tri-fold Memory Card Wallet - Stores up to 3 Memory Cards, Dust Removal Blower System, 3pc. Lens Cleaning Kit, 77mm UV Protective Filter MINIMUM FOCUSING DISTANCE of 11 inches throughout the entire zoom range. MAGNIFICATION RATIO of 1:5. FOCAL LENGTH from 17mm wide angle and offers a large aperture of F2.8 throughout the entire zoom range.