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. The new Opteka High Definition II .20x Wide Angle Fisheye Converter Lens increases the versatility of your existing lens to provide breathtaking ultra wide angle views. And it"s so easy to use! Great for every type of photographic situation! Converts a 18-55mm into a 3.6-11mm Circular Lens Opteka lenses put more creative control where it belongs - in your hands.