Danny Boyle learned "about film acting" by watching Michael Fassbender on the set of 'Steve Jobs'.
The acclaimed director, whose previous film credits include 'Trainspotting' and 'Slumdog Millionaire', has revealed he was wowed by Fassbender and Kate Winslet's performances in the eagerly-awaited biopic about the co-founder of Apple.
He shared: "I learned more about film acting. Especially these two [Michael Fassbender and Kate Winslet].
"A lot of it is their mental preparation. And it's not about slavishly learning lines, though in this case it was, because of the nature of it. But the execution of it is simple, in a way.
"They just step into it. It was extraordinary. There's no demarcation: 'Stop that fun, everybody! Stop everything! Action!' It was just, like, 'Go!'"
The British filmmaker also said it was "extraordinary" watching Fassbender's character evolve through the course of the movie.
He told Variety: "That was real film acting, and I loved kind of recording it, watching it happen. And something extraordinary happens to Fassbender in act three where he just is the guy.
"We set out not to make it slavish and gestural with the hair and everything, because that would be boring and we'd be concentrating on that. We just wanted to flow into it."