on a bell

Prepositional phrase

(film) Warned by the ringing of a bell to remain silent during a period of shooting.

Japanese Meaning

映画撮影現場で、ベルの音によって撮影中の静粛が求められる状況を示す表現

During filming we were on a bell, falling silent at every ring until the shot was complete.

撮影中はベルの合図で、ベルが鳴るたびにショットが終わるまで静かにしていました。

Sense（1）

(film) Warned by the ringing of a bell to remain silent during a period of shooting.

[…] and putting the set "on a bell," the First Assistant Director will call "Roll 'em!"