Sigma 10-20mm F4-5.6 EX DC HSM
Overall the Sigma 10-20mm F4-5.6 EX DC HSM is a solid, well-built lens with good operational characteristics, which justifies its popularity with generally decent imaging results. While its long-running unique selling point of being the only third-party 10mm zoom has now disappeared, and it faces strong competition from Tamron's 10-24mm, the different characteristics of the two lenses means it's still a good option for APS-C users looking for the widest of ultra-wideangle zooms.
Cropped sensor shooters looking for an affordable, well-built super wide angle zoom lens.
People who are picky about barrel distortion, or shoot in a lot of low-light environments.