John Walker was the film cameraman for several Doctor Who television stories. He also played a villager in the BBV Productions home video story Auton 2: Sentinel and was the uncredited film camera assistant on The Krotons (INFO: The Krotons) and The War Games. (INFO: The War Games)
He was interviewed on the documentary Troughton in Tibet, as well as the audio commentary for The Abominable Snowmen's DVD and Blu-ray release.