Kubrick was among the first directors to use video assist during filming. At the time he began using it in 1966, it was considered cutting-edge technology, requiring him to build his own system. Having it in place during the filming of "2001", he was able to view a video of a take immediately after it was filmed. On some films, such as "Barry Lyndon", he used custom made zoom lenses, which allowed him to start a scene with a close-up and slowly zoom out to capture the full panorama of scenery and to film long takes under changing outdoor lighting conditions by making aperture adjustments while the cameras rolled. LoBrutto notes that Kubrick's technical knowledge about lenses "dazzled the manufacturer's engineers, who found him to be unprecedented among contemporary filmmakers". For "Barry Lyndon" he also used a specially adapted high-speed (f/0.7) Zeiss camera lens, originally developed for NASA, to shoot numerous scenes lit only with candlelight. Actor Steven Berkoff recalls that Kubrick wanted scenes to be shot using "pure candlelight", and in doing so Kubrick "made a unique contribution to the art of filmmaking going back to painting ... You almost posed like for portraits." LoBrutto notes that cinematographers all over the world wanted to know about Kubrick's "magic lens" and that he became a "legend" among cameramen around the world.