The Sigma 17-70mm F2.8-4 DC Macro OS HSM Lens is a large-aperture lens with a maximum f/stop of f/2.8 in wide angle setting. The large zoom range of this 4x zoom lens (equivalent range of approx. 27-112mm when used with a Canon digital SLR camera) makes it ideal as an everyday large-aperture lens. In addition, the minimum focus distance of 8.7" along with the maximum magnification of 1:2.7 also makes the lens perfect for close-up photography.

Optical Stabilization (OS) anti-shake technology allows you to use shutter speeds approximately 4 stops slower than would otherwise be possible, without motion blur. This anti-shake technology, along with the fast f/2.8 to 4 aperture, makes this lens perfect for shooting in low light without a tripod.