This is the accumulation of all the new optical technologies Canon has, embodied in the next-generation L-type large-aperture 300mm, with a newly designed optical system. One fluorite lens element and two UD lens elements are used to thoroughly eliminate secondary spectrum. High picture quality with high resolution and high contrast is achieved. The world’s fastest*¹ autofocusing has been achieved by employing a ring-type USM and improving the drive algorithm. Furthermore, equipping the lens with an image stabilizing mechanism that compensates for roughly two shutter speeds*² has made it possible to get the best performance out of it under all conditions. The closest focusing distance has also been reduced to 2.5m / 8.2ft. Operability has been greatly advanced by adding an AF stop button and revamping the focus preset method. Using a magnesium alloy for the lens barrel has resulted in an ultra lightweight body which is 295 grams lighter than before. The body has outstanding dust-proof*³ characteristics. It comes with a removable tripod collar.