1. The biggest difference between performing on stage and performing for the camera is the location of your audience. The second major difference between stage and camera acting is the familiarity of the material. Theater is by its very nature repetitive and therefore familiar. The third difference between stage and TV/Film is the iconic nature of the characters and celebrated performances of those characters.
  2. The film is the directors medium because they have to form it and sculpt it to fit what they want it to be portrayed.