Sigma 50mm f/1.4 DG HSM Art Lens for Nikon F

Key Features Aperture Range: f/1.4 to f/16 One Molded Glass Aspherical Element Three Special Low Dispersion Elements Super Multi-Layer Coating Floating System & Large Diameter Design Hyper Sonic AF Motor Rounded Nine-Blade Diaphragm Thermally Stable Composite Material Brass Bayonet Mount Compatible with Sigma USB Dock