This is a description of the Sigma 24-70mm f/2.8 DG DN Art Lens, which is designed for Sony E-mount mirrorless cameras. The lens has a bright f/2.8 maximum aperture, which is useful for working in low light and controlling depth of field. The optical design includes six F Low Dispersion (FLD) and two Special Low Dispersion (SLD) elements, as well as three aspherical elements, which help reduce chromatic aberrations and distortion, resulting in high sharpness, clarity, and color accuracy. Super Multi-Layer and Nano Porous Coatings have also been applied to minimize lens flare and ghosting, and to produce contrast-rich and color-neutral images, even in backlit conditions.
The lens has an integrated stepping motor for quick and quiet autofocus, which is complemented by an optimized AF algorithm for smooth focusing performance. At the wide-angle end of the zoom range, the lens can focus as close as 7.1″ with a maximum magnification of 1:2.9, making it suitable for close-up photography. At the telephoto end, the minimum focusing distance is 1.25′ with a maximum magnification of 1:4.5.
The lens also has an AF-L button that can be programmed to adjust various shooting settings, a dedicated AF/MF switch, and a zoom lock switch to prevent the barrel from accidentally extending. The 11-blade diaphragm contributes to a pleasing bokeh quality, and the brass bayonet affords improved mounting accuracy and rigidity. The mount is also designed with rubber sealing to make it dust- and splash-resistant, making it suitable for use in harsh environmental conditions.