The Sigma 200-500mm f/2.8 EX DG lens is a professional-level telephoto zoom lens made by Sigma Corporation. It is notable for being the first lens with an aperture of f/2.8 and a focal length of 500mm. This combination allows very distant objects to be photographed at high shutter speeds in dimmer light, compared to other telephoto lenses. It also allows for very narrow depth-of-field and diffuse bokeh. The main markets for such long, fast lenses are wildlife and sports photographers.