Sigma's ultra-wide for APS-C — the 10-20mm HSM covering dramatic wide angles.
The Sigma 10-20mm f/3.5 EX DC HSM is the constant f/3.5 version of Sigma's popular APS-C ultra-wide zoom — faster than the f/4-5.6 version (ID 3428). The constant f/3.5 is a genuine advantage over variable alternatives. HSM for quiet AF. Covering 15-30mm equivalent on APS-C. Mount not specified. A strong budget ultra-wide option.
Good optical quality. The constant f/3.5 is the key advantage — brighter and more consistent than variable-aperture alternatives. Sharpness good throughout. HSM motor fast and quiet. The 15-30mm equivalent covers dramatic ultra-wide territory. EX professional build. Better than the variable-aperture version at all focal lengths.
Mount not specified — verify. Available in Canon EF-S, Nikon F, Sony A, and Pentax K. Filter thread 77mm. Weight approximately 520 grams. EX build quality. HSM motor. The constant f/3.5 version is preferred over the variable f/4-5.6. No image stabilisation.
Verify mount. The constant f/3.5 is preferred over the variable version. HSM motor. Good quality budget ultra-wide. The 77mm filter enables standard filters. Check AF. One of the better budget APS-C ultra-wide zooms from the DSLR era.