https://www.npr.org/transcripts/959609533
GLINTON: OK, so the first brilliant idea that Lucy and Desi came up with involved the technology of television. They had learned on tour that comedy, if it's going to be done well, had to be captured live in the moment in front of an audience.
SMITH: Desi says, we want three cameras, which was unheard of at the time. We want three cameras to be rolling to capture all of the reactions and the ad libs and the hat flying off the top of my head, just like they had done on tour.
GLINTON: And those cameras with the three operators, they said, we don't want that grainy kinescope stuff. We want luxurious, beautiful 35 mm film like they use in motion pictures.
SMITH: The three-camera sitcom shot on film is a standard today. Think of it. In the early 1950s, in one big leap, "I Love Lucy" suddenly looked and felt modern.
GLINTON: But it was not cheap. Desi and the studio got into this huge fight over who was going to pay for those three cameras, three cameramen and all that rolling film. Eventually, Desi made an offer. He'll pay for the filming, but he and Lucy will own the film reel, the actual shows themselves.