Sigma 17-70mm F2.8-4 DC OS HSM is an Auto Focus (AF) Standard Zoom
lens with APS-C / DX max sensor coverage and it is designed to be used with Canon EF mount cameras.
Lenses in Canon EF Mount with Same Focal and Aperture Range
Sigma 17-70mm F2.8-4 DC OS HSM is compatible with cameras that have Canon EF
lens mount. Some of the latest released cameras with Canon EF lens mount are
Max sensor coverage of Sigma 17-70mm F2.8-4 DC OS HSM is APS-C / DX
Sigma 17-70mm F2.8-4 DC OS HSM has a focal range of 17-70mm and 4.1X zoom ratio.
Optical Image Stabilization
Sigma 17-70mm F2.8-4 DC OS HSM features an optical image stabilization system which helps to reduce the blur that occurs due to shaking during hand-held shooting.
Sigma 17-70mm F2.8-4 DC OS HSM 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.
Sigma 17-70mm F2.8-4 DC OS HSM is a variable aperture lens with a max aperture of f2.8 and a minimum aperture of f22 at 17mm, and a max aperture of f4 and minimum aperture of f32 at 70mm .
Sigma 17-70mm F2.8-4 DC OS HSM's optical formula consists of 17 elements in 13 groups.