The Magnavox Magnavision VLP optical videodisc player shown in the film was Lew Wasserman's personal player and was borrowed from his office for the day of shooting. It was a hand-built pre-production model that was given the "7000" model number. The entire top of the player opens instead of just a small "lid" portion and the disc area has a clear window so you can see the disc spinning. For the final player release (model 8000), the lid was shrunk to only the disc area and the transparent window was eliminated. The player used in the film could not play CLV Extended Play discs as the the CLV format had not yet been finalized. The single-sided disc placed on the player contained the actual recording of James Stewart seen in the film - MCA Disco-Vision pressed the one-off disc just for the film. The packaging for the disc is a so-called "Nautilus Box" inside a standard cardboard box used to transport MCA Records Nickel-plated LP stampers. Monica Lewis uses the player incorrectly. She doesn't shut the lid completely and presses one of the "audio" buttons instead of the "Play Forward" button.
Joan Crawford was approached to play the role of Emily Livingston but declined, later saying, "I wanted Joel McCrea to play opposite me, and anyway, they actually asked me to fly out there with only one week's notice! Why, that is hardly enough time for makeup tests or rehearsals... and when I asked about costume fittings, they said they wanted me to wear my own clothes!"
To prepare for his role, Jack Lemmon attended both diving school and flight training school. As Jack Lemmon stated for his flight training, "I wanted to know what all the knobs and dials were for."
Greer Garson was also offered the role of Emily Livingston but she had not made a feature film in ten years and so she declined, preferring to continue making guest appearances on television.