The EF 500mm f/4L IS II USM is a newly-developed, light-weight, large diameter, super-telephoto lens, that features completely redesigned optics to provide better image quality and significant weight reduction. It is also equipped with Canons Image Stabilisation function, making it equivalent of 4 shutter-speed settings faster. The EF 500mm f/4L IS II USM is an ultra high-performance lens that combines superb ease-of-use with excellent durability made for the digital age.