Standard zoom is designed for full-frame Canon EF-mount DSLRs, however can also be used with APS-C models where it provides a 38.4-112mm equivalent focal length range.
Bright constant f/2.8 maximum aperture affords consistent illumination throughout the zoom range and also affords greater control over depth of field for working with selective focus techniques.
One Super Ultra-Low Dispersion element and two ultra-low dispersion glass elements noticeably reduce color fringing and chromatic aberrations for high clarity and color fidelity.
Three aspherical elements minimize spherical aberrations and distortions for improved sharpness and accurate rendering.
Super Spectra coating has been applied to individual elements to minimize ghosting and flare for greater contrast and color neutrality when working in strong lighting conditions.
A ring-type Ultrasonic Motor (USM), along with an internal focusing design, optimized focusing algorithms, and a high-speed CPU, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override.
Rounded nine-blade diaphragm contributes to a pleasing out of focus quality that benefits the use of shallow depth of field and selective focus techniques.
Protective fluorine coating has been applied to the front and rear element to resist fingerprints and smudges and to make cleaning these elements significantly easier.
As a member of the esteemed L-series, this lens is sealed against dust and moisture for working in inclement environmental conditions.
Zoom lock lever secures the zoom position at the wide end to maintain a compact form factor and protect the lens when not in use.

Canon