Overview

The Canon EF-S 17-85mm f/4-5.6 IS USM is a versatile walk-around zoom for APS-C bodies, offering a useful 27-136mm equivalent range and effective 3-stop image stabilization. Optical strengths include good sharpness and quick, quiet USM autofocus. Weaknesses are significant distortion, especially at 17mm, and high vignetting wide open. Build quality is solid plastic with a metal mount, but feels less premium than L-series lenses. It suits photographers seeking a stabilized, all-in-one lens for travel and general use, though newer designs offer better optical performance.