Sigma's older APS-C constant f/2.8 standard zoom — pre-OS version without stabilisation.
The Sigma 18-50mm f/2.8 EX DC is a constant f/2.8 APS-C standard zoom for Nikon F-mount DX, covering 27-75mm full-frame equivalent. HSM autofocus. 72mm filter thread. 0.20m MFD. Compact design for an f/2.8 standard zoom.
Eighteen elements in 13 groups (SLD and high-refractive elements). Seven aperture blades. The 72mm filter thread. Minimum focus distance of 0.20m. HSM motor for fast, quiet AF. f/2.8 constant aperture. DC APS-C image circle. Nikon F DX mount.
The 18-50mm f/2.8 EX DC covers the standard zoom range for Nikon DX at constant f/2.8, providing consistent aperture from 27mm to 75mm equivalent. The 0.20m MFD enables close foreground compositions at the wide end. The compact design for an f/2.8 standard zoom prioritised portability over long zoom range.
On the used market the Sigma 18-50mm f/2.8 EX DC is affordable as a vintage APS-C f/2.8 standard zoom for Nikon. Condition checks: HSM AF response, 72mm front element for marks, zoom ring smoothness. DC APS-C only. Compatible with Nikon F-mount DX bodies.