The Sigma APO 120-300mm F2.8 EX DG HSM a truly unique product which is a rarity in the photo industry. This lens is the only lens of its kind on the market; a professional zoom lens that also features a fast aperture. Most professionals own the standard 300mm 2.8, but they also have to carry a shorter zoom lens for those times when the subjects move closer. That means fumbling around switching lenses or carrying a second camera body. The amazing Sigma zoom lens let you instantly determine the picture composition you want without having to change your vantage point. Imagine photographing courtside at a college basketball game and having the versatility to zoom in on a player’s face or hand and then instantly zoom back to capture the entire player making his shot. You can do it with the Sigma APO 120-300mm F2.8 EX DG HSM. The aperture remains constant at F2.8 throughout the entire zoom range.

• Designed for use with full frame digital SLR cameras. May also be used with smaller APS-c size sensors with a corresponding effective increase in focal length to about 180 to 450mm with most cameras
  
  
• HSM (Hyper-Sonic Motor) ensures a quiet & high-speed auto focus
  
  
• Four SLD (Special Low Dispersion) glass elements provide optimum color correction & sharpness throughout the entire zoom range
  
• Inner focusing System eliminates front lens rotation & suitable for use of polarizing filters
  
  
• Compact weighing only 5.7 pound & a mere 11 inches in length
  
  
• Compatible with the Sigma APO Tele Converters