The Sigma 500mm f/4 DG OS HSM Lens takes its spot as the flagship in the speedy Sports line. This super telephoto lens lets you capture distant subjects, and with a speedy Hyper Sonic AF motor users w espandi...ill be able to easily track fast action. A relatively fast maximum aperture of f/4 furthers your imaging potential with excellent illumination for a lens of this class. One SLD and two FLD elements help ensure outstanding optical performance by minimizing aberrations and distortion while a Super Multi-Layer coating combats flare and ghosting.