Sigma 18-50mm f/2.8 EX DC HSM Macro Lens for Nikon DSLR (OLD MODEL) A minimum focusing distance of 20cm (7.9"), a maximum magnification of 1:3 Large aperture of F2.8 throughout the entire zoom range Special Low Dispersion (SLD) and Extraordinary Low Dispersion (ELD) Compact and lightweight lens Reduced Ghosting and Flare The super multi-layer lens coating reduces flare and ghost. High image quality is assured throughout the entire zoom range HSM (Hyper-Sonic Motor) ensures a quiet and high-speed auto focus