Nothing changes the way you see the world like High Definition II, and no company does High Definition II like Opteka. In the professional setting, Opteka's glass optics define High Definition. Change the way you view the world. Enjoy outstanding detail, enjoy enhanced clarity, enjoy Opteka. Since it fits right over your camera's existing lens system, a telephoto converter affects the zoom range of your camera's lens. A 2x converter will double your camera's maximum focal length, bringing things twice as close.