The Canon 24-105mm f/4L IS EF USM AF Lens is an easy-to-use standard zoom lens that can cover a large zoom area ranging from 24mm wide-angle to 105mm portrait-length telephoto. The EF 24-105mm f/4L IS USM incorporates Canon's highest standards of precision optics. The L-series is Canon's flagship professional lens range, combining outstanding image performance and ultimate operability with dust and moisture resistant construction. Canon's ring-type USM gives silent but quick AF, along with full-time manual focus. Moreover, with dust- and moisture-resistant construction, this is a durable yet sophisticated lens that meets the demands of advanced amateur photographers and professional photographers alike. Image Stabilizer Ideal for handheld work, IS Image Stabilizer allows use of shutter speeds up to 3-stops slower with no perceptible increase in image blur. Fixed Aperture With no change in aperture over the full focal length range, photographers can set exposure at the widest aperture and zoom through to 105mm without slowing shutter speed. Super UD and Aspherical Lens Elements Constructed with one Super-UD glass element and three aspherical lenses, this lens minimizes chromatic aberration and distortion. The result is excellent picture quality, even at wide apertures. Ring USM Ring USM (Ultrasonic motor) uses ultrasonic frequency vibrations to drive responsive, near-silent high speed auto focus. Good holding torque stops the focusing lens group with precision without overshoot. Full time manual focus override is available without having to switch out of AF. Super Spectra Coatings Optimized Super Spectra lens coatings and lens element shaping suppress flare and ghosting - more prone to occur with digital cameras due to reflection off the image sensor. Coatings also help achieve true color balance and increase contrast for vivid hi-fidelity images.