Cooke Varotal 20-100mm T3.1

Lens designer Gordon H. Cook designed the 35mm Cooke 20-100mm, T3.1 Varotal zoom lens, released in 1971. It was the first high quality zoom designed for professional motion picture photography that incorporated a totally new design concept that has remained the basis for all Cooke zoom lenses subsequently produced. It was produced through the late 1980s.