Covering a flexible ultra-wide range, the Canon EF-mount 10-20mm f/3.5 EX DC HSM from Sigma is a versatile zoom well-suited for landscape, architectural, and interior photography. The lens's optical design incorporates a series of low dispersion and aspherical elements, which help to reduce chromatic and spherical aberrations throughout the zoom range, as well as contribute to improved sharpness and clarity. A Super Multi-Layer Coating is also used to suppress flare and ghosting for improved contrast and color accuracy. Benefitting the imaging attributes, a Hyper Sonic Motor also affords quick and quiet autofocus performance as well as full-time manual focus override.