Sigma's mid-range APS-C zoom with macro — 25.5-105mm equiv at f/2.8-4.5 with HSM motor.
The Sigma 17-70mm f/2.8-4.5 DC Macro HSM launched in 2006 as an APS-C standard zoom with macro capability. Starting at f/2.8 wide and narrowing to f/4.5, it offered more speed than kit lenses with useful close-focus ability.
Optically good — sharp in the centre with the f/2.8 wide end useful for low light. The macro mode provides close-focus versatility. HSM motor for quiet AF. The 17-70mm range is wider and longer than typical 18-55mm kits.
Available for multiple APS-C DSLR mounts. 72mm filter thread. Approximately 455g. No weather sealing. Macro mode. DC — APS-C only. HSM motor. Variable f/2.8-4.5.
Available used very cheaply. The later 17-70mm f/2.8-4 DC Macro OS HSM improved with OS stabilisation and constant f/4 at the long end. For budget APS-C users wanting more range and speed than kit lenses.