The Sigma 24-35mm f/2 DG HSM Art lens is the world's first constant f/2 aperture on a full-frame zoom lens. The groundbreaking aperture combined with the versatile wide-angle 24-35mm focal length allows photographers to easily replace three common lenses, the 24mm, 28mm, and 35mm, with one piece of gear. The lens also offers exceptional control over depth-of-field with an aperture range from f/2 to 16, and when used on APS-C camera bodies it has an equivalent focal length of 38.4-56.
Along with the rest of the Art series, the 24-35mm offers high quality optics with the use of one "F" Low Dispersion and seven Special Low Dispersion glass elements in addition to two aspherical lenses. This system minimizes the appearance of spherical aberration, axial chromatic aberration and field curvature. A Super Multi-Layer Coating is present to reduce flare and ghosting for sharp, high-contrast images and it can focus as close as 11".
In terms of speed, this lens is equipped with a Hyper Sonic AF Motor which is nearly silent and has an optimized autofocus algorithm for fast, accurate tracking. The body of the 24-35mm is constructed of a Thermally Stable Composite material which performs well in all conditions. The barrel also has a focus ring with grants full-time manual override and the system is designed for completely internal focusing. Further ensuring optimal performance is compatibility with Sigma's USB Dock for firmware updates and AF microadjustment.