The people behind the trick

1915. Filming The Warrens of Virginia, the director Cecil B. DeMille borrowed spotlights from a Los Angeles theatre and lit only half of an actor's face. His business partner worried that cinemas would pay only half price for half a face. DeMille called it Rembrandt lighting, after the Dutch painter who sometimes lit faces that way, and the name stuck.

Try it with a desk lamp: put it a little above and to one side of a friend's face, and look for a small triangle of light on the far cheek.

Told by DeMille in his autobiography (1959).