Biography: Best known for his color photographs of nature, Porter taught himself to photograph and to make black and white prints as a teenager. By the mid-1930s he was a master printer. He began working in color in 1939 and was focused on color photography by the mid-1950s. He experimented with the complex early techniques for color printing, eventually mastering dye transfer printing and using that technique for the rest of his career. Porter's beautiful nature photographs helped to convince skeptical critics and collectors that color photography could be used for artistic expression.