Sigma's early DX ultra-wide — the 10-20mm f/4-5.6D version with screw-drive AF for Nikon.
The Sigma 10-20mm f/4-5.6D EX DC HSM is an early version of Sigma's APS-C ultra-wide zoom for Nikon F mount with D-type coupling. Described in other mount versions under ID 3428, it covers 15-30mm equivalent with HSM quiet AF. The D designation indicates Nikon AF coupling compatibility. An affordable ultra-wide for DX DSLRs.
Optical performance is decent for the era. Centre sharpness is good. HSM provides quiet AF. The 15-30mm equivalent range provides dramatic wide-angle perspectives. The variable f/4-5.6 aperture limits low-light use. DG coatings reduce sensor reflections. The later constant f/3.5 version is preferred for its faster, consistent aperture.
Nikon F mount, APS-C. Filter thread is 77mm. Weight is approximately 470 grams. Build quality is solid EX professional. HSM motor for quiet AF. No image stabilisation. The 77mm filter thread accepts standard filters — an advantage over bulbous ultra-wide designs. The constant f/3.5 version supersedes with a faster aperture.
Very affordable. Check HSM and zoom. Superseded by the constant f/3.5 version and modern alternatives. Adequate for budget DX ultra-wide work. The 77mm filter thread is a practical advantage. Best at very low prices for casual ultra-wide photography.