original_query: What technique did Toland use to create partial shadow on the actors' faces?
query: What technique did Gregg Toland use to create partial shadow on the actors' faces in The Life and Death of 9413: a Hollywood Extra?
answer: During close-ups, the actors held the single 400-watt light bulb used for filming to illuminate their faces.  Switching the bulb from hand to hand as they changed position resulted in partial shadows on their features.