I did a film once that I was killed in. It was a painful, horrifying day. It was a wonderful day from the standpoint of acting, but I was a wreck otherwise.
A good movie is made by an initial burst of energy, the way that, when you are in school, your class exercises are always better than your final projects.
Most theater methodology is predicated on the idea of repeated actions. That's what you work toward. Having the actor repeat the same moment eight times a week. In a film, it's getting that one moment right.