Film and television acting is more of a science than an art, in my opinion.
Not to belittle the brilliance of the many talented performers who grace our movie screens and TV sets every year, but acting for 'the lens' requires lots of other very specific abilities. Of course it's about creating a voice and becoming the part to make the viewer believe you 'are' the character being portrayed, but it's also about finding your light and hitting marks and maintaining eye lines and understanding lenses and knowing edge of frame...I could so go on and on. Not to mention NOTHING is performed continuously top to bottom, but rather in little bits and pieces all filmed out of order.
Generating a performance is very important. Conveying that performance effectively to the audience within the parameters and constraints of the filmed medium...as if not more important. More math than method...again, in my opinion.
That's why the 'Acting In Film' series with Michael Caine is so money, and should be required viewing for every aspiring (and even established) thespian. Caine's all about less is more, craft not art, and in a straightforward and understandable way drops dozens of helpful hints to make the camera love you.
Here's a taste:
Michael Caine On Acting In Film...I own the book and DVD and recommend them to anybody, but you find find some of the best video bits HERE (parts 1-6)