The Nikon F mount Sigma 50mm f/1.4 DG HSM Lens is a fast standard-length prime designed to achieve high optical performance by incorporating three Special Low Dispersion glass elements and one molded glass aspherical element. These elements, coupled with an advanced optical design, minimize sagittal coma flare and chromatic aberrations to provide high image sharpness and clarity. The lens' large diameter and floating system also help to correct for vignetting to ensure maintained peripheral brightness. A Hyper Sonic AF Motor, along with an optimized AF algorithm, produces quiet, smooth, and fast autofocus performance that benefits this lens' use in a wide variety of situations. As part of the Art line within Sigma's Global Vision series, this lens is designed to achieve truly notable optical performance and is ideally suited for creative and artistic applications. A molded glass aspherical element corrects for sagittal coma flare and enables the full use of the fast f/1.4 maximum aperture with maintained sharpness and clarity. This design also works to minimize vignetting, color blur, and other distortions helping to produce natural and pleasing bokeh for selective focus and shallow depth of field techniques. Three SLD (Special Low Dispersion) glass elements have been incorporated within the lens design to correct for axial chromatic aberration throughout the entire focusing range. This design also lends itself to minimizing vignetting throughout the aperture range for greater clarity and detail across the image frame. By employing a floating system, the distance between glass elements is adjusted during focusing to limit the amount of lens movement required when shooting. This floating system helps to realize a minimum focusing distance of 1.3' with a maximum magnification of 1:5.6. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time.
Sigma 50mm F/1.4 DG HSM Art Specs