Details from the Canon news release:
Canon introduces the new EF 70-200mm f/2.8L IS II USM lens. The body structure of the new EF 70-200mm f/2.8L IS II USM lens has been enhanced to provide better durability and strength without a significant increase in weight. Canon has improved optical performance on the new EF 70-200mm f/2.8L IS II USM lens by redesigning the internal elements, incorporating a fluorite element and a fifth UD element. The use of the fluorite element and five UD elements helps to minimize secondary chromatic aberrations and produce better image quality with improved contrast and resolution through the entire zoom range.
Along with its redesigned optical elements, the new lens design features improved AF speed due to a new focusing algorithm and has reduced the minimum focusing distance to 3.9 feet (1.2 meters) through the entire zoom range. The previous lens models minimum focusing distance was 4.6 feet (1.4 meters), whereas now photographers can stand nearly 8 inches closer to their subject and achieve sharp focus and tight crops. Canon has also enhanced the Image Stabilization allowing it to compensate for shutter speeds up to four steps slower than 1/focal length, a one step improvement over the previous lens model.
The enhanced magnesium alloy barrel design of the EF 70-200mm f/2.8L IS II USM lens features added strength with a minimal 20-gram increase in weight compared with the previous model (1490g vs. 1470g) and retains Canons protective seals and fittings providing dust and water resistance for those photographers working in adverse conditions. A new bayonet mount on the front of the lens includes a locking mechanism to ensure the supplied lens hood remains securely in place. Other noticeable improvements include a wider focusing ring, and sleeker design by reducing the thickness of any protruding elements such as the switch panel. The new lens is also compatible with Canons existing EF1.4X II and EF2X II Extenders as well as EF Extension Tubes and the 77mm Close-Up Lens 500D.
Pricing and Availability
The Canon EF 70-200mm f/2.8L IS II USM lens is supplied with a detachable tripod collar, a reversible bayonet mount lens hood and a lens pouch. The new lens is scheduled to be delivered to U.S. dealers in April, price to be determined.