Due to a tight filming schedule many of the special effects scenes of where Dr Westin would undress on camera by removing or putting on his 'synthetic skin' adornments were actually done live on set. A camera would be set up and locked off in a studio where the scene was supposedly taking place whilst David McCallum would be filmed in the opposite corner of the same studio wearing a blue body suit against a blue background watching the action live and interacting appropriately with the rest of the actors on the other set. The camera crew superimposed him in real time onto the live other scene using the chroma key technique (similar to how weather forecasters work when standing in front of a blue/green screen whilst the data appears behind them). This not only saved a considerable amount of time in post production but also saved money. However, the downside was that as the two images were filmed and recorded live, there were limited options for the editing crews to use and sometimes the quality of the merged video images appeared a bit fake (for example skin tones often did not look right) and it was impossible to correct due to the technical limitations of electronic television camera & videotape technology of the time.