The EF 70-300mm f/4.5-5.6 DO IS USM Lens from Canon is a relatively compact telephoto zoom offering superior maximum-aperture performance across its entire focal length range. It incorporates Canon's DO (Diffractive Optics) and IS (Image Stabilizing) technologies. The use of Diffraction Optics allows a lens to be shorter, lighter, and of higher image quality than comparable normal optical systems of the same focal length and aperture-while this lens is heavier than the consumer-grade EF 70-300mm f/4-5.6 IS USM lens, it is 28% shorter and uses Canon's very best ring-USM (ultrasonic) motor instead of the lighter, slower, and less costly 'micro-USM' motor. The DO lens performs admirably at its maximum aperture, with images that are very comparable to the "L" series telephotos. It has a circular aperture diaphragm to help create natural out-of-focus highlights, and its built-in two-mode image stabilizer allows you to handhold the lens at shutter speeds 3 steps slower than would otherwise be possible. Mode 1 corrects vibrations in all directions and is best for still subjects whereas Mode 2 is best when following moving subjects either horizontally or vertically. The lens' AF is super-fast and silent with a ring-type USM that focuses down to 4.6', and it enables manual focus override for precise manual focus even in AF mode. It also features a zoom lock button that keeps the lens safe and secure when not in use or when being used at the shortest 70mm focal length setting. The EF 70-300mm f/4.5-5.6 DO IS USM is an ideal lens for sports, portraiture, animals, and other applications when you're shooting in relatively bright light. An autofocus telephoto zoom lens for both film and digital camerasExcellent maximum-aperture performance across entire zoom rangeBuilt-in two-mode image stabilizer action can be seen in the viewfinder and allows handheld images at shutter speeds 3 steps slower than without image stabilizationFast, silent autofocus with full-time manual focus overrideDiffractive Optics elements are combined to minimize aberrations, boost image quality and reduce the lens' overall length.With rear focusing, the lens does not change length or rotate during focusing.Compact form factorCircular aperture diaphragm for natural-looking out of focus
