Sigma's stabilised APS-C superzoom — 27-300mm equiv with OS in a compact package for Canon DSLRs.
The Sigma 18-200mm f/3.5-6.3 DC OS launched in 2007 as Sigma's stabilised APS-C superzoom, covering 29-320mm equivalent on Canon. The addition of OS (Optical Stabilisation) was a significant improvement over the unstabilised DC version.
Optically adequate for a superzoom — acceptable centre sharpness at mid-focal lengths with softness at the extremes. OS provides approximately 4 stops of stabilisation — essential at the long end. HSM motor on some versions for quiet AF. DC designation means APS-C only.
Canon EF-S mount with 62mm filter thread. Approximately 405g — lightweight. No weather sealing. Minimum focus distance 45cm. APS-C coverage only. The OS version represented a meaningful upgrade over the non-stabilised Sigma 18-200mm.
Available used very cheaply. Later versions improved further. The Tamron 18-200mm VC is the main competitor. Acceptable as a budget one-lens travel solution. Check for smooth zoom action. The stabilisation makes handheld shooting at 200mm practical.