Sigma APO 500mm with OS and HSM for Canon, colour-corrected super-telephoto at potentially better value than newer alternatives.
The Sigma 150-500mm f/5-6.3 APO DG OS HSM for Canon EF is a super-telephoto zoom with APO glass, OS stabilisation, and HSM autofocus covering 150-500mm. The APO glass provides superior colour correction that the later 150-600mm Contemporary and Sport replaced with improved designs.
The 500mm provides genuine super-telephoto reach with APO colour correction and OS stabilisation essential for handheld telephoto. The HSM motor provides fast, quiet AF, and the DG full-frame coverage works on both APS-C and full-frame Canon bodies.
Build quality is quality Sigma with the APO, OS, and HSM designations indicating comprehensive specification. The 150-500mm predates the 150-600mm but provides similar super-telephoto capability at potentially lower used pricing.
The Sigma 150-500mm APO OS for Canon offers APO-corrected super-telephoto at affordable used pricing. The 500mm reach with OS and APO provides genuine wildlife capability — potentially better value than the newer 150-600mm at used market prices.