Good and bad acting
What's the difference?
Marlin Brando, Robert Duvall and Rod Steiger, on separate occasions, were all asked the question, "what's the difference between great actors and good actors?" They all gave the same answer:
For the great actor, it's really happening to him.
On a simple level the answer is whether the viewer forgets that it is an actor working and becomes so absorbed into the character and the world they inhabit that they get taken along on their emotional journey.
In order for us to believe who you are and what you're doing you must first believe it yourself. As the Joker in Batman, Heath Ledger had to believe that the events which led up to him being totally screwed up were real. Everything was motivated by the back story and history he had worked on. The end result of this hard work is personality, spontaneity, and a huge amount of believability and as such we as viewers are drawn further in to the action.
Ledger told reporters he "slept an average of 2 hours a night" while playing "a psychopathic, mass murdering, schizophrenic clown with zero empathy…I couldn't stop thinking. My body was exhausted, and my mind was still going."
I guess it depends how far you are willing to go to fully inhabit the role you are playing. Committing 100% may push you towards the edge but there is a lower percentage which would be ideal. Michael Ferguson in his Headstrong approach talks about the relationship between your Inner Actor and Inner Character, whereby the actor balances the character thoughts and their own (around an 80/20 split being ideal). When they inhabit the character and think their thoughts we believe them, but when they are trying to remember lines, blocking or, even worse, pushing for an emotion, we don't and consequently drop out.
It's not about pretending. Good acting is as seamless as if you're listening to an interesting emotive conversation between 2 people on the street who are not aware of being observed. Of course a good script helps.
It is easy to notice horrible acting. Give one of your non-actor friends a scene and ask them to read it with some emotion and see for yourself. They might have some natural ability but it is more than likely you will not be sucked in. They will indicate, gesture and fake it and you will spot it a mile off.
It's that feeling you have when you have watched a play, film or TV show and didn't enjoy it but don't know why. More than likely it will be that the actors didn't believe what they were saying so the viewer couldn't connect with them.
Here is a compilation of great movie actors doing great movie acting.