The Canon EF-S 24 mm - 70 mm f/2.8L II USM Standard Zoom Lens is designed to fulfill your digital photographic needs. It features a large aperture throughout its focal length and utilizes 1 Super UD lens element and 2 UD lens elements that help minimize chromatic aberration in the periphery at wide-angle as well as reduced color blurring around the edges of the subject. In addition, 2 types of aspherical lenses are combined to reduce spherical aberration over the entire image area as well as through the full zoom range. Plus, the lens is also equipped with a circular 9-blade diaphragm for beautiful, soft backgrounds. Also it ensures an enhanced color balance while minimizing ghosting with optimized lens coatings. Besides this, it's constructed with dust sealing and water resistance while fluorine coatings on the front and rear lens surfaces help reduce soiling, smears and fingerprints. Packed with all these and more, this Standard Zoom Lens makes it easy to throw backgrounds out of focus, grab details, or approach subjects you'd rather not get too close to.