Sigma 24-70mm F2.8 EX DG is an Auto Focus (AF)
Standard Zoom lens with 35mm FF max sensor coverage and it is designed to be used with Sigma SA mount cameras.
Lenses in Sigma SA Mount with Same Focal and Aperture Range
Lens Mount
Sigma 24-70mm F2.8 EX DG is compatible with cameras that have Sigma SA lens mount.Some of the latest released cameras with Sigma SA lens mount are
Sigma Quattro,
Sigma Quattro H and
Sigma SD1 Merrill.
Sensor Coverage
Max sensor coverage of Sigma 24-70mm F2.8 EX DG is 35mm FF.
Focal Range
Sigma 24-70mm F2.8 EX DG has a focal range of 24-70mm and 2.9X zoom ratio.
Optical Image Stabilization
Sigma 24-70mm F2.8 EX DG doesn't have an optical image stabilization system so the only option to stabilize the image taken with this lens is to mount on a camera body with IBIS (sensor based In-body image stabilization).
Zoom Method
Sigma 24-70mm F2.8 EX DG features Rotary (extending) zoom method where the length of the lens changes as you zoom in or out. This makes it possible to design the lens with a smaller minimum length ( generally when it is zoomed out) compared to internal zoom lenses. The disadvantages of this design are being harder to seal against dust and moisture, weight balance shifting while zooming and zoom creep in certain lenses.
Aperture
Sigma 24-70mm F2.8 EX DG is a fixed aperture lens with a constant max aperture of f2.8 from 24mm all the way to the 70mm .
Optical Formula
Sigma 24-70mm F2.8 EX DG's optical formula consists of 14 elements in 13 groups.