Sigma’s APO 200-500mm F2.8/400-1000mm F5.6 EX DG, is the first large-aperture ultra telephoto lens to have an F2.8 aperture at 500mm. With its specially designed attachment mounted becomes a 400-1000mm F5.6 ultra telephoto lens capable of auto-focus shooting. It has ELD (Extraordinary Low Dispersion) and SLD (Special Low Dispersion) glass for maximum correction of aberrations. Perfect fast moving nature subjects and sports such as surfing, polo and soccer and as it excels at tracking fast moving objects it is a great surveillance lens. Here, Sigma’s achievement is unsurpassed and stands alone.