O ne drawback of shooting on film was that the results couldn’t be reviewed until the footage had been processed at a laboratory. This occasionally meant that the crew had to return to a location days or weeks later to remount a sequence deemed unsatisfactory, as happened with the climactic attack of the Nestene creature in Spearhead from Space.
Doctor Who began making use of the videotape-based OB (Outside Broadcast) technology a few years later. In Steve Cambden’s book The Doctor’s Effects, visual effects designer Tony Oxley remembered the recording of The Sontaran Experiment (1975) on Dartmoor: “The cameras back then were quite big and were linked by cables to a mobile recording van at the bottom of the tor. It was a great luxury to see whatever we had just recorded and decide on the spot whether we needed to do it again.”