This lens is ideal for sports and wildlife photography. The newly designed optical system has one fluorite element and two UD-glass elements to obtain high resolution and high contrast. Also, the minimum focusing distance was reduced to 18 ft. (5.5m). Extender EF 2x II can be attached to increase the focal length to 1200mm while retaining AF (at the center focusing point with the EOS-1v and EOS-3).
Unless you are with other avid/pro photographers (or alone), expect stares and lots of questions from those around you when using the Canon EF 600mm f/4.0 L IS USM Lens. It garners lots of attention. Respond politely and don’t worry about it. Then show them the pictures you have taken with your 600. As they say, a picture is worth a thousand words. And in the hands of a good photographer, the Canon EF 600mm f/4.0 L IS USM Lens will create pictures that generate lots of admiration.