The Sigma 105mm f/1.4 DG HSM Art Lens for Leica L-Mount is a short-telephoto, portrait-length prime lens that is characterized by its bright maximum aperture & advanced optical layout. Its fast f/1.4 design assists with working in low-light conditions & also provides extensive control over depth of field for isolating subjects (and working with selective focus). This lens is also designed for high-resolution rendering, & uses FLD and SLD glass to control chromatic aberrations & color fringing for notable clarity. A Super Multi-Layer Coating also improves image quality by suppressing lens flare & ghosting for improved contrast & color fidelity in strong lighting scenarios. Its rounded nine-blade diaphragm contributes to a pleasing "bokeh" quality. Its Hyper Sonic Motor produces smooth, quick, & quiet autofocus performance with full-time manual focus override. The physical design uses Thermally Stable Composite material for durability in a range of environments, & its brass bayonet mount also offers durability & mounting precision. For working with a tripod, a removable tripod collar is also included, and features an Arca-type foot for wide mounting compatibility.