Older full-frame wide-angle zoom lens with aspherical elements.
The Sigma 17-35mm f/2.8-4 EX Aspherical is a wide-to-standard zoom from Sigma's EX (Excellence) professional range, designed for full-frame 35mm film and DSLR cameras. The variable aperture ranges from f/2.8 at 17mm to f/4 at 35mm. The EX designation indicates Sigma's professional-grade optical and mechanical construction; aspherical elements reduce distortion across the zoom range.
17–35mm zoom range, f/2.8-4 variable maximum aperture, EX professional construction, aspherical elements, Nikon F mount, full-frame coverage.
The Sigma EX 17-35mm provides a wide-to-standard zoom range useful for landscape, architecture, and environmental photography on full-frame Nikon cameras. The f/2.8 at 17mm is useful for low-light wide-angle work. Optical quality is competitive for its era and price tier, though later Sigma designs (including the 17-35mm f/2.8 II and the 12-24mm range) superseded it.
Inspect for fungus, haze, and coating condition. Test zoom and focus operations. Confirm Nikon F mount engagement. Check aperture blades. Test at 17mm and 35mm extremes for sharpness and corner performance.