Sigma has expanded their ever growing Global Vision line with the world 's first constant f/2 aperture on a full-frame zoom lens, the24-35mm f/2 DG HSM Art Lens, available here with the Canon EF lens mount. 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.