Obituary: Petro Vlahos

Inventor Petro Vlahos (b.1916) died on February 10. Vlahos arrived in Hollywood after World War II and helped create blue- and green-screen compositing, which was used in movies including Star Wars and Raiders of the Lost Ark. In 1964, he won an Oscar for his work on Mary Poppins and later served as a technical advisor for the film Battle Beyond the Stars.