Sigma's early full-frame ultra-wide zoom — 17-35mm at f/2.8-4 with aspherical elements for Nikon F.
The Sigma 17-35mm f/2.8-4 D EX DG Aspherical launched in 2001 as a budget full-frame ultra-wide zoom for Nikon F mount. It covered a useful 17-35mm range with aspherical elements to control distortion and aberrations at a significantly lower price than the Nikon 17-35mm f/2.8D.
Optically acceptable for its era — sharp in the centre at mid-apertures but with noticeable edge softness, particularly at 17mm. The variable f/2.8-4 aperture is reasonably fast at the wide end. D-type communication for metering. EX designation — quality construction.
Nikon F mount with 82mm filter thread — large for the era. Approximately 660g. No VR stabilisation. Full-frame coverage. DG designation means full-frame optimised. Aspherical elements help control distortion. Minimum focus distance 50cm.
Very cheap used — a budget way to get full-frame ultra-wide coverage on Nikon F mount. The Nikon 17-35mm f/2.8D and later 16-35mm f/4G VR are significantly better. Modern alternatives have vastly improved. Only for ultra-budget needs. Check for haze and fungus on older copies.