Telephoto lens newly equipped with an Image Stabilizer enabling hand-held shooting for easier movement. The fluorite element and two UD-glass elements effectively correct the chromatic aberrations prone to occur with telephoto lenses. With the EOS-1v and EOS-3, the AF speed becomes the worlds fastest. To reduce the overall weight and enhance portability, the lens barrel and many other exterior parts use a magnesium-alloy. Also, the detachable tripod collar revolves smoothly and locks securely.