The Sigma 17-40mm F1.8 Dc | Art builds upon the groundbreaking innovations of the Sigma 18-35mm F1.8 Dc Hsm | Art, which earned high acclaim as the world's first F1.8 zoom lens in the photography and video industry. Thirteen years after its debut, this next-generation lens achieves not only superior optical performance but also a wider focal length of 17-40mm while reducing its weight by over 30%. This dramatically enhances the versatility of a large aperture standard zoom lens.In addition to the fast and quiet autofocus driven by the Hla (High-response Linear Actuator), the lens incorporates an inner zoom mechanism and minimal focus breathing, ensuring outstanding performance for both still photography and video production. Sigma, the pioneer that stunned the world with the first-ever F1.8 zoom lens, has once again revolutionized the history of large aperture zoom lenses with groundbreaking advancements.