Complementing the optical performance, the lens is also characterized by its ring-type USM and internal focusing mechanism to enable quick, quiet, and precise autofocus performance along with full-time manual focus override. A dedicated macro position also enables focusing as closely as 7.9" away in order to achieve a 0.7x magnification for photographing close-up subjects. A four-stop-effective Image Stabilizer is also used to minimize the appearance of camera shake for sharper handheld shooting. Additionally, this lens is weather-sealed and has a protective fluorine coating on the exposed elements for use in trying environmental conditions.
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.
Constant f/4 maximum aperture maintains consistent illumination throughout the zoom range.
Two ultra-low dispersion glass elements noticeably reduce color fringing and chromatic aberrations for high clarity and color fidelity.
Two 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.
An Optical Image Stabilizer helps to minimize the appearance of camera shake by up to four shutter speed stops to better enable working in low-light conditions and with slower shutter speeds.
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.
Minimum focusing distance of 1.2' is available throughout the zoom range and a dedicated macro position can be used to achieve a maximum magnification of 0.7x in conjunction with a minimum focusing distance of 7.9".
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.