How does a cinema determine when to turn the auditorium lights off and on when screening a movie? Do cinemas have any appreciation for the film when deciding when to flick the on/off light switch? Or are they just robotic in their care for the nuances of each movie they screen.
By law, cinemas must have adequate lighting for moviegoers to see where they are going within an auditorium - pre, during, and post screening. Most cinemas have lights up until the trailers start then they switch to half-up, when the feature starts lights, normally, go off except for aisle and exit lights.
Now, the vast majority of cinemas have automated lighting and dimmer systems interfaced to the projection system, so rarely does a human exercise discretion over the lighting on/off or dimming.
There is a credits off-set time on the actual hard drive the movie arrives on and which is ingested into the projection server. The cinema places a cue in their automation system, which will bring down or up the lights at a precise moment in the presentation.
No two lighting systems are going to be the same from cinema to cinema and when many of today's films have med-credit and post-credit sequences when to bring up the lights is iffy. For example, Marvel movies feature multiple post-credit sequences which set-up the next sequel in the superhero series. Many comedies have blooper scenes that run after the feature is over. However, lights will normally come-up automatically for those moviegoers wishing to exit the auditorium right after the feature ends.
So far as I know, no cinema has separate lighting policies for different genres of film - they simply set the cue according to their on-going practice. It is the policy of each cinema, guided by law, that set the lighting rules.
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