Kenko 400mm f/8 Mirror Lens for Micro 4/3 Mount Cameras The Kenko mirror 400 mm F8 super tele lens for Micro 4/3 Mount Cameras is extremely compact and lightweight. Useful for those who prefer shooting active scenes and have some sub super telephoto lens along with primer lenses. When shooting birds, animals or flora, the Kenko mirror 400 mm is ideal.