There are times movie fans and viewers of the annual Oscar telecast could be forgiven for thinking there was an award for Best Imitation.

Last night the Academy of Motion Picture Arts and Sciences awarded at least the 12th acting Oscar this decade to someone portraying an actual person when Sean Penn won the award for Best Actor for playing Harvey Milk.

There is acting skill required in bringing to the screen an effective and convincing performance based on a real person, but its only because film and television archives are full of material about well-known figures that we can judge how effectively this was done.

When an actor can spend endless hours studying every step in a person’s gait, every nuance of their gestures, every characteristic of their speech, is it acting or imitation?  When those they play are living, and they can spend time with them to understand their motivations, feelings or attitudes, is it as much an imitation as an act?

We can judge Helen Mirren’s Queen Elizabeth II, or Forest Whitaker’s Idi Amin, or Phillip Seymour Hoffman’s Truman Capote effective only because the characters are so familiar to us all.

It should be the true mark of acting excellence when an actor creates a character from whole cloth.  Real acting acumen is demonstrated when a character’s development is organic; when every sound, every step, every expression was imagined and incorporated to create a whole person.

That’s why, for example, Mickey Rourke’s Randy “The Ram” Robinson this year, or Heath Ledger’s Ennis Del Mar in 2005 should have secured a statuette.

Hopefully next year’s celebration of movie excellence will rediscover this standard before honoring a new series of acting nominees.