The EF24-70mm f/2.8L II USM features a new optical design that includes three aspherical lens elements, one Super UD lens element, and two UD lens elements to minimise the incidence of various forms of aberration that can occur when zooming and at the image periphery at the wide end. UD lenses also contribute to the elimination of colour blurring around the subject for high image resolution and contrast. Lens coatings have been optimised to ensure outstanding colour balance while also minimising the incidence of ghosting commonly associated with digital photography.
A smaller and lighter (804g) body has been achieved, saving 10.5mm in length and 145g in weight compared with its predecessor. While offering a large diameter, the lens length is just 113m in the wide-end position.
Again in response to feedback from professionals, the lens features a Zoom Ring Lock Lever which keeps the lens locked in the wide-end position to prevent it from extending inadvertently when moving around between shots. Advanced autofocus (AF) features include a ring USM drive, a high-speed CPU and an optimised AF algorithm for fast, silent autofocusing. Moreover, a full-time mechanical manual focus, even in AF mode, enables more detailed focussing by allowing users to manually adjust focus by rotating the focussing ring immediately after autofocusing.