The Nikon F-mount 135mm f/1.8 DG HSM from Sigma pairs bright and sophisticated optics with intuitive handling and design. As part of the Art line of lenses, this 135mm f/1.8 is designed for high-resolution rendering and utilizes FLD and SLD glass to control chromatic aberrations and color fringing for notable clarity.  Additionally, making it an ideal lens for portraiture, the bright f/1.8 maximum aperture pairs with a rounded nine-blade diaphragm to benefit selective focus and shallow depth of field imaging with smooth bokeh. 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. Bright f/1.8 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. 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. 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 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. The lens is constructed using a Thermally Stable Composite (TSC) material, along with traditional metals, for greater precision and use in wide temperature variations.