Squinting in the Moonlight

Do you squint in the moonlight because it's too bright? Neither do I. And neither does anyone else, except for the characters on TV shows from the 1950s and budget-sensitive (cheap) "B" movies. Why? Because of a cinematic technique called "day for night."The same section of my cerebrum wondered why the headlights of Perry Mason's car gave off so little light as he and Paul Drake arrived at a midnight crime scene. And I certainly wondered why everyone was squinting.In fiction writing, we have a concept called willing suspension of disbelief. It amounts to a mutual agreement: the storyteller agrees to lie and the audience agrees to believe it. But the storyteller is still obligated not to do anything that would pull the reader/listener/viewer out of the story.
No credible fiction writer wants the reader to be pulled out of the story. But if the viewer of that episode of M*A*S*H was born after the 60s, they would need an unusually sharp cultural awareness to pick up on the error. But it will happen with older viewers. The seams will start to show.
When you underexpose film, everything is darker. Depending on what is in the shot, the technique works. But if the shot includes a light source, believability is blown out of the water because campfires and headlights are darkened along with everything else.