Sigma 28-45mm F1.8 Dg Dn Art full-frame zoom lens - a fast, portable and versatile large aperture zoom lens with the sharpness and clarity of a prime lens. The Sigma 28-45mm f1.8 Dg Dn Art Lens allows users to move with a lot of creative freedom and flexibility. This artistic lens captures stunning photos and videos for various situations and settings, making it especially appealing for Sony E-Mount and L Mount havers.World's First Full-Frame, F1.8 Zoom LensThe 28-45mm F1.8 Dg Dn Art Lens from Sigma is the first to offer a really wide aperture of F1.8 across its entire zoom range. Such a wide aperture lens means it allows more light to go inward, guaranteeing any user a great photo even in bad lighting.18 Elements in 15 GroupsInside the lens are different types of glass elements arranged in special groups. It has 5 Special Low Dispersion glass elements and 3 aspherical elements which banish chromatic aberrations and optical distortions respectively.