The 300-800mm f/5.6 EX APO IF HSM is currently the longest zoom lens made by any manufacturer, and ideal for nature/outdoor or sports photography.
This extreme telephoto zoom lens provides a relativley large constant f/5.6 maximum aperture at all focal lengths. The use of Apochromatic design and 2 ELD (Etraordinary Low Dispersion) glass elements give full correction of chromatic aberration and provide a high level of optical performance. The AF drive for the Canon EOS, Nikon and Sigma mounts are equipped with the silent, responsive and high speed Hyper Sonic Motor and provides fulltime manual focus override. A tripod mount is provided with the lens.
It is possible to use this lens with Sigma 1.4x EX and 2x EX Apo Tele Converters to convert this lens into an ultra tele-zoom lens, effectively converting it into a 420-1120mm f/8 or 600-1600mm f/11 lens. The lens materials used in this new lens are lead and arsenic free ecological glass.