The EF-S 17-85mm f/4-5.6 IS USM Lens from Canon is a lightweight, compact all-purpose "standard " zoom lens with a focal length equivalent to 27-136mm in the 35mm format. It is compatible with DSLR cameras that use the APS-C format and provides a versatile set of focal lengths from wide-angle to telephoto.

This lens features Canon 's optical Image Stabilization technology, providing up to a 3-stop compensation for image blur caused by camera shake at slow shutter speeds. A ring-type ultrasonic autofocus motor provides fast and silent autofocus action and full-time manual focus is supported even when in the AF mode.

Designed specifically for digital photography, it has a 17 element, 12 group construction, including one double-sided aspherical element for reduced aberrations and crisp, high contrast corner-to-corner detail. Canon 's specialized lens coatings suppress ghosting and flare and an optional dedicated lens hood can further reduce the incidence of flare. A rounded 6-blade aperture provides pleasing out-of-focus backgrounds when shooting with a shallow depth of field.