John Finger

John Finger was a cinematographer who acted as director of photography for the first two days of filming on the  episode, replacing Al Francis, who was unavailable for part of the shoot due to illness. He was not credited on-screen for his contribution. 

Finger was mostly known for his work on sitcoms, having been the regular director of photography on fellow Desilu Productions show Gomer Pyle, USMC at the same time that TOS was in production. He was also a frequent collaborator with noted sitcom director James Burrows, serving as the director of photography on nearly every episode of Cheers (starring Kelsey Grammer, Kirstie Alley, and Bebe Neuwirth) and its spin-off The Tortellis, along with the pilot episodes of Valerie and Dear John. Marvin V. Rush and Howard Block frequently served as his camera operators during this period.

Outside of his sitcom work, Finger was also the director of photography for Saul Bass's title sequence on the film West Side Story (directed by Robert Wise, starring Richard Beymer).