The Sigma 300-600mm F4 DG OS | Sports zoom lens is a revolutionary ultra-telephoto lens with high brightness that offers all the performance and versatility of a zoom lens combined with the superior optical quality of a fixed focal length ultra-telephoto lens. With the Sigma 300-600mm F4 DG OS | Sports, you can quickly switch between 300mm and 600mm focal lengths without changing lenses. The AF performance of its high-response linear motor (HLA) and 5.5 stops of optical stabilization at 600mm make the Sigma 300-600mm F4 DG OS | Sports the ideal lens for sports, action, and wildlife photography—genres where situations change rapidly, and the chance for the perfect shot lasts only a few moments. Featuring a magnesium alloy body, thermal insulating paint, and a range of additional features like the new function ring, the Sigma 300-600mm F4 DG OS | Sports is designed to help professionals achieve their goals more effectively. -- **Super Telephoto Zoom Lens with Fixed Focal Length Performance and Brightness** Exceptional versatility in ultra-telephoto shooting. The Sigma 300-600mm F4 DG OS | Sports extends the possibilities of a 600mm fixed focal length F4 by adding a zoom capability back to 300mm without compromising optical performance. Its internal zoom mechanism minimizes center of gravity shifts throughout the zoom range, making it a versatile and easy-to-use tool for an unprecedented range of shooting situations. -- **Top-level Optical Performance** The Sigma 300-600mm F4 DG OS | Sports features 28 elements in 21 groups, including 6 FLD glass elements and 1 SLD glass element, which provide anomalous dispersion and a high refractive index. Its optical design ensures excellent correction of various types of aberrations, including chromatic aberration, throughout the zoom range. Despite being a zoom lens, the Sigma 300-600mm F4 DG OS | Sports delivers optical performance comparable to that of corresponding fixed focal length lenses. -- **High-Speed Autofocus and Powerful Optical Stabilization to Capture Decisive Moments** High-speed AF with HLA motor. Despite its wide F4 aperture, the Sigma 300-600mm F4 DG OS | Sports uses a focusing lens group that, thanks to the HLA (High-response Linear Actuator) system, optimizes optical power and glass quality. The result is exceptionally precise, high-speed autofocus functionality. -- **Powerful Optical Stabilization with OS2 Algorithm** The Sigma 300-600mm F4 DG OS | Sports provides exceptional 5.5-stop optical stabilization at 600mm. Powered by Sigma's sophisticated OS2 algorithm and equipped with a drive unit featuring a specially designed actuator and a high-precision sensor, this lens meets the demands of a large-aperture ultra-telephoto lens with ease. Additionally, users can choose between two operating modes: Mode 1 is suitable for most photographic and video shooting, while Mode 2 is particularly designed for panning shots. Guided by Sigma’s intelligent OS system algorithm, this mode stabilizes the image during horizontal, vertical, or diagonal movements, regardless of the camera's orientation, enabling precise tracking of moving subjects. -- **Durability and Portability** The main barrel components are made from magnesium alloy, and the lens hood is made of carbon to ensure both high durability and lightness. Additionally, the design centers the lens’s balance toward the camera, significantly improving handling. **Lens Coating with Thermal Paint for Consistent High Performance** The exterior of the lens body is coated with a thermal insulating paint that prevents the lens from overheating, even during long outdoor shooting sessions in sunny conditions, as often happens in wildlife or motorsport photography. **Multi-Function Ring for Enhanced Shooting Options** The Sigma 300-600mm F4 DG OS | Sports is equipped with a function ring that enhances operational convenience. It offers two different modes, which can be set via the dedicated switch: - **Preset Focus Mode**: By rotating the function ring left or right, the focus can instantly shift to a preset focus position. This is useful when frequently shooting subjects at a fixed distance from the shooting point. - **Constant Focus Mode**: Constant focus adjustment is possible by operating the function ring, allowing smooth focus shifts during video shooting and minimal focus movement when shooting handheld. The focus speed can be adjusted depending on the ring's rotation angle. **Robust, Easy-to-Use Tripod Mount** The tripod mount rotation mechanism uses bearings for extended durability and smoother rotation, with a precise click/de-click mechanism for each 90° rotation. The tripod mount foot is compatible with Arca-Swiss clamps but can be easily removed and replaced with various interchangeable tripod mounts (sold separately) to better suit user preferences. **Drop-In Filter Holder** The Sigma 300-600mm F4 DG OS | Sports is equipped with a drop-in filter holde