Key features Outstanding optical performance Building on the reputation of the existing SIGMA 50mm F1.4 DG HSM | Art as one of the highest-performing standard zooms on the market, this new mirrorless optic delivers even sharper results across the frame, particularly towards the periphery. Employing the latest optical design technology, the lens is constructed of 14 elements in 11 groups, including one SLD (Special Low Dispersion) element and three apsherical elements. It delivers significant improvements to sagittal coma flare and effectively suppresses various aberrations such as astigmatism and field curvature, which cannot be corrected digitally. This new standard prime boasts an ultra-wide aperture of F1.4, making it ideal for low-light photography such as concerts, interiors and weddings. It also delivers a very shallow depth-of-field for background blur, which is perfect for creating stand-out portraits. The bokeh is smooth and attractive, and thanks to the lens’s 11 diaphragm blades, the out-of-focus highlights are nicely rounded. Even when working wide-open at F1.4, photographers can be assured of razor-sharp edge-to-edge results. All-new ultra-fast AF motor The SIGMA 50mm F1.4 DG DN | Art is the first DG DN lens in the Art line to incorporate Sigma’s new HLA (High- response Linear Actuator) autofocus motor technology. This ensures fast, accurate and near-silent focusing, and despite its ultra-wide aperture, exceptionally fast tracking performance. Owing to the power of the new HLA motor, Sigma engineers were able to use a single double-sided aspherical element as the focusing lens – a stark contrast to the eight-element focusing group on Sigma’s existing 50mm F1.4 DG HSM | Art. This has delivered both autofocus and optical design benefits. Robust but compact design Throughout the development of the SIGMA 50mm F1.4 DG DN | Art every effort was made to slim down the lens barrel by reducing the weight of the focus lens and optimising the lens unit layout. This allowed Sigma to create a light and compact lens that feels well-balanced on a full-frame mirrorless camera without compromising on optical performance. The lens’s build quality is superb, and meets the very high standards you would expect from a Sigma Art line lens. With a dust- and splash-resistant structure, a rubber seal around the mount, and a water- and oil-repellent coating on the front-element, the 50mm F1.4 DG DN | Art is suitable for use in difficult shooting conditions. The outer barrel is constructed of TSC (Thermally Stable Composite), which has a similar thermal expansion rate to aluminium. This means the metal inner barrel and the TSC outer barrel behave in a similar way as temperatures change, ensuring a consistent performance in all environments. Both materials are very light, with the lens weighing just 670g (L-Mount version). As with all Sigma lenses, the 50mm F1.4 DG DN | Art is crafted using cutting-edge manufacturing technology at Sigma’s sole factory in Aizu in Japan. Every single lens is evaluated with Sigma’s proprietary MTF measuring system before leaving the factory, ensuring consistenly excellent products that photographers can rely on. Advanced feature-set designed for professional use The lens barrel is equipped with a range of useful functions. As well as a manual aperture ring, the lens has an Aperture Ring Click switch, which allows users to switch between stepped, third-stop aperture increments and a smooth, click-free action. This is particularly useful for videographers who may want to use the aperture to adjust exposure seamlessly while filming. The aperture ring can be locked with lock switch. The lens has an AFL button, which can be customised to perform a range of different functions (depending on camera model). Also on the lens barrel is an Focus Mode switch, a rubberised focus ring with a smooth, fluid-like movement, and a robust, petal-type lens hood with lock button. The hood also has a rubberised grip for easy attachment and removal. For L-Mount users, the 50mm F1.4 DG DN | Art can be connected to Sigma’s USB Dock for customisation and adjustment, including switching between linear and non-linear focus ring movement.