Overview

The Canon EF-S 17-55mm f/2.8 IS USM is a high-quality general-purpose zoom for APS-C Canon DSLRs, offering a fast constant f/2.8 aperture and 3-stop IS. Optically, it is decently sharp wide open and very sharp at f/4, but chromatic aberration is high at wide angles and vignetting is noticeable at f/2.8. Build includes ring USM for quick, quiet AF and full-time manual focus. It suits enthusiasts wanting a fast standard zoom with good image quality, though third-party alternatives may offer better sharpness at f/2.8.