Sigma's popular APS-C standard zoom — f/2.8-4 with OS and macro, predecessor to the Contemporary.
The Sigma 17-70mm f/2.8-4 DC Macro OS HSM launched in 2009 as a versatile APS-C standard zoom. Starting at f/2.8 wide with OS stabilisation and macro close-focus, it offered more capability than kit lenses in a practical package.
Optically good — sharper than kit zooms with f/2.8 at the wide end. OS provides approximately 4 stops. HSM motor for quiet AF. Macro mode at 20cm provides close-up versatility. The 17-70mm range covers 25.5-105mm equivalent.
Available for multiple APS-C DSLR mounts. 72mm filter thread. Approximately 470g. No weather sealing. OS stabilisation. HSM motor. Macro mode. The Contemporary version later refined the design.
Available used very cheaply. The Contemporary version improved optics and build. The 17-50mm f/2.8 OS is faster throughout. A practical mid-range upgrade over kit lenses for APS-C DSLRs.