The Canon EF-mount 100-400mm f/5-6.3 DG OS HSM Lens is a telephoto zoom within Sigma's Contemporary series that blends both a refined optical design with a compact and lightweight physical construction. On the optical front, this zoom utilizes four SLD glass elements to noticeably reduce chromatic aberrations and color fringing throughout the zoom range for improved clarity and color accuracy, and a Super Multi-Layer Coating has also been applied to increase contrast when working in strong lighting conditions. The physical design utilizes Thermally Stable Composite material for durability in a wide range of environments; both twist and push-pull zoom mechanisms are available for improved control over field of view; and a brass bayonet mount also offers rigidity and mounting precision. The telephoto zoom lens is designed for full-frame Canon EF-mount cameras, however can also be used with APS-C models where it will provide a 160-640mm equivalent focal length range. 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 optical Stabilizer system minimizes the appearance of camera shake to benefit from making sharper imagery when shooting handheld. The front lens element has been treated with a water- and oil-repellent coating to benefit working in harsh environmental conditions. This lens is compatible with the optional Sigma USB Dock for fine-tuning different lens characteristics and updating its firmware.