Sigma's earlier 24-70mm f/2.8 for DSLRs — pre-Art line with HSM motor and EX professional build.
The Sigma 24-70mm f/2.8 EX DG HSM was the pre-Art era constant f/2.8 standard zoom for full-frame Canon EF and Nikon F bodies, released approximately 2008. Fourteen elements in 12 groups including aspherical, ELD, and SLD elements. HSM autofocus. At 790g and 82mm filter thread. Nine rounded aperture blades. 0.38m MFD.
The optical design uses 14 elements in 12 groups including 3 aspherical, 1 ELD, and 2 SLD elements. Nine rounded aperture blades. The 82mm filter thread. At 790g the lens is moderate. Minimum focus distance of 0.38m. HSM motor provides fast, quiet AF with full-time manual override. Constant f/2.8 aperture. Full-frame coverage.
The EX DG HSM 24-70mm was Sigma's professional standard zoom before the Art-series redesign: the HSM motor and ELD/SLD correction elements provided competitive optical and autofocus performance at a lower price than Canon and Nikon equivalents of the same era. The Art-series 24-70mm f/2.8 DG HSM (2013) succeeded it with significantly improved optical correction at f/2.8 across the frame.
On the used market the Sigma 24-70mm f/2.8 EX DG HSM is very affordable as a vintage full-frame standard zoom. Condition checks: HSM AF response, 82mm front element for marks, zoom ring smoothness. Confirm Canon EF or Nikon F mount version. Compatible with full-frame and APS-C bodies in the specified mount.