Terrorform - S5-E3
Visible crew/equipment: A boom mic shadow can be seen along the bottom of the screen when the crew have to leave Starbug and walk. (00:11:25)
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Terrorform - S5-E3
Visible crew/equipment: When Lister, Cat and Kryten leave the cockpit with the plan to make Rimmer feel good about himself to escape, a boom mic can be seen in the top left corner of the screen. (00:22:45)
Terrorform - S5-E3
Visible crew/equipment: When Lister and the Cat type into the computer, in the shots of their reflections, the lens of the camera can be seen reflected between them. (00:05:00)
Answer: The cello is a large four-stringed instrument, which, when it is played, stands vertically on the floor between the player's legs (assuming they are seated). If it is to grow as large as the other instuments mentioned will, it would require a rather unseemly lack of femininity to be able to encompass it with the legs.
Rooster of Doom