Sigma 80-400mm f/4.5-5.6 EX OS APO RF Telephoto Zoom Lens for Sigma SLR Cameras Fixed F4 aperture throughout the entire zoom range Ideal for digital and 35mm SLR cameras Features SLD (Special Low Dispersion) glass elements for superior correction of chromatic aberration Hyper Sonic Motor (HSM) for ultra-quiet shooting Capable of full-time manual focus