I only had three hours of sleep last night, two hours the night before, maybe three before that. When there's a major changeover I can instantly powernap for 15 minutes. The two pics below are from Making The Video Sisqo Thong Song where I slept on set overnight as it got rained out. I'm pointing out the proper Director technique of powernapping. See the perfect posture of the head taken twenty years apart. This cannot be learned. Either you have this talent or not. Perfect execution. (Photo by my AD Michael Kahn who ordered an unnecessarily expensive Irish steak on my dime in Portugal tonight)