The Sigma 17-70mm F2.8-4 DC Macro OS HSM is a premium fast 'normal' zoom for APS-C SLRs, which is designed as an upgrade for photographers who have outgrown the 'kit' zooms typically supplied with camera bodies. It was announced at Photokina 2012, as the first lens in Sigma's new 'Contemporary' category of compact general-purpose zooms for everyday photography. It's a successor to a near identically-named lens from December 2009, the Sigma 17-70mm F2.8-4 DC Macro OS HSM, but is smaller and lighter, uses revised optics, and has a new cosmetic design. Prior to this Sigma made the unstabilised 17-70mm f/2.8-4.5 DC, a lens which was very highly regarded in its time.