The 28-70mm f/2.8 DG DN Contemporary Lens for Sony E-Mount from Sigma is a versatile wide-angle to portrait-length zoom characterized by its f/2.8 constant maximum aperture. The design suits working in available lighting conditions while affording increased control over depth of field. More lightweight and compact than similar 24-70mm lenses, it's optical design incorporates two FLD and two SLD low-dispersion elements plus three aspherical elements that reduce a variety of aberrations to achieve high sharpness, enhanced clarity, and improved color accuracy. It features just one lightweight focusing element, which keeps the AF unit small. This, along with a quiet and fast stepping motor, makes for responsive and near-silent autofocus performance, an ideal combination for filmmakers looking for a high-performance, lightweight, and easy-to-handle camera system that works well with a gimbal or other accessories.

Each optical surface features Super Multi-Layer and Nano Porous coatings to improve contrast and color rendering by suppressing lens flare and ghosting for optimal light transmission, and an added water- and oil-repellent coating on the front optic helps keep the lens free from smudges and droplets. The weather-sealed design benefits working in trying environmental conditions, and a nine-blade rounded diaphragm contributes a pleasing bokeh quality when using wider apertures.
Standard zoom for full-frame E-mount mirrorless cameras
 36-105mm equivalent focal length when used on an APS-C camera
 Constant f/2.8 maximum aperture for Low light use and depth-of-field control
 Two F Low Dispersion (FLD) and two Special Low Dispersion (SLD) elements reduce chromatic aberrations and color fringing
 Three aspherical elements control spherical aberrations and distortion
 Both Super Multi-Layer and Nano Porous coatings minimize lens flare and ghosting and produce contrast-rich and color-neutral imagery
 Integrated stepping motor and optimized AF algorithm provides quick and quiet autofocus
 28mm minimum focus distance: 7.5", 1:3.3 magnification
 70mm minimum focus distance: 15", 1:4.6 magnification
 Rounded nine-blade diaphragm for a pleasing bokeh quality
 Brass bayonet for mounting accuracy and rigidity
 Rubber sealing for dust- and splash-resistance