Fast and versatile, the Sigma 50mm f/1.4 DG HSM Art is a normal-length prime designed to achieve high optical performance through the incorporation of both three Special Low Dispersion glass elements and one molded glass aspherical element. These elements, coupled with an advanced optical design, work to minimize sagittal coma flare and chromatic aberrations in order 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 Super Multi Coating has been applied to lens elements, too, to reduce flare and ghosting for higher contrast and color fidelity. Additionally, making it an ideal lens for portraiture, the bright f/1.4 maximum aperture pairs with a rounded nine-blade diaphragm to benefit selective focus and shallow depth of field imaging with smooth bokeh.

Complementing the imaging capabilities, the lens sports a Hyper Sonic Motor to produce quick, smooth, and quiet autofocus performance with full-time manual focus override. The physical design utilizes Thermally Stable Composite material for durability in a wide range of environments, and a brass bayonet mount also offers rigidity and mounting precision.

• 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.
• Prime normal-length lens is designed for full-frame cameras, however it can also be used with APS-C models where it will provide a 75mm equivalent focal length.
• Bright f/1.4 maximum aperture is well-suited for working in low-light conditions and also provides greater control over the focus position when using shallow depth of field techniques.
• Three Special Low Dispersion (SLD) elements are featured in the optical design, and help to reduce color fringing and chromatic aberrations for improved clarity and color accuracy.
• One aspherical element reduces distortion and spherical aberrations for improved sharpness and accurate rendering.
• A Super Multi-Layer Coating has been applied to lens elements in order to minimize lens flare and ghosting and contribute to producing contrast-rich and color-neutral imagery, even in backlit conditions.
• Nine-blade rounded diaphragm contributes to a smooth and pleasing bokeh quality.
• The integrated HSM (Hyper Sonic Motor) realizes quick and quiet autofocusing, which is further complemented by an optimized AF algorithm to produce smoother focusing performance. The HSM also permits full-time manual focus control simply by rotating the focus ring at any time.
• The lens is constructed using a Thermally Stable Composite (TSC) material, along with traditional metals, for greater precision and use in wide temperature variations.
• The bayonet mount is constructed from brass for ensured accuracy and durability.
• Additionally, rubber sealing is incorporated in the mount design to render it dust- and splash-resistant.