Sigma's early wide-angle zoom in Sony A mount — the 17-35mm f/2.8-4 EX DG.
The Sigma 17-35mm f/2.8-4 EX DG HSM is the Sony A-mount version of Sigma's early wide-angle zoom also listed in Nikon F under ID 3581. The variable f/2.8-4 aperture starts fast at the wide end. Designed for full-frame coverage, it provided affordable wide-angle zoom capability for Sony/Minolta A-mount photographers.
Optical performance is decent for the era. Centre sharpness is good at wider focal lengths. DG coatings optimise for digital sensors. HSM motor provides fast, quiet AF — important on A-mount where body-drive AF can be noisy. The EX designation indicates Sigma's professional build tier. Corner performance improves when stopped down.
Sony A mount (Minolta A compatible). Filter thread is 82mm — large. Weight is approximately 660 grams. Build quality is solid with EX professional construction. No image stabilisation — benefits from Sony's SteadyShot INSIDE on compatible A-mount bodies. The 17mm wide end provides useful ultra-wide coverage on full-frame.
Available on the used market at low prices — the A-mount system's declining demand keeps prices affordable. Check AF operation and smooth zoom. Superseded by much better modern alternatives. Only of interest to A-mount system owners wanting affordable wide-angle zoom coverage. Adapts to E-mount via LA-EA adapters.