The Sigma 300-800mm f/5.6 EX DG HSM is an extreme telephoto zoom lens, and ideal for nature/outdoor or sports photography. This lens provides a relatively large constant f/5.6 maximum aperture at all focal lengths.
The use of Apochromatic design and 2 ELD (Extraordinary 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.
The improved DG lens design corrects for various aberrations. This lens is specially coated to get the best color balance whilst cutting down on ghosting caused by reflections from the digital image sensor. The lens provides the utmost correction against lateral chromatic aberration which is a serious problem for digital SLR cameras.
It is also 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.