NEW YORK (Reuters) - Every day before filming began on "The Theory of Everything" Eddie Redmayne would gaze at three photos to help him convey the essence of Stephen Hawking, the brilliant British scientist he portrays in the film.
The 32-year-old actor had spent months working on portraying the near total physical paralysis of the astrophysicist and author of "A Brief History of Time," who suffers from amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease.
But Redmayne ("Les Miserables") knew he had to project Hawking's wit, lady's man charm and mischievous glint, hence the photographs of Albert Einstein sticking out his tongue, actor James Dean and the joker in a pack of cards.
"They would sit on my trailer wall and before going to work I would take a last glance and remember to find that glint," he said.
"The Theory of Everything," which opens in select U.S. theaters on Friday, is a love story that chronicles Hawking's romance and marriage to his first wife, Jane, played by British actress Felicity Jones ("The Amazing Spider-Man 2"), and is based on her memoir.
It begins with their meeting at Cambridge University in the 1960s, his diagnosis at age 21 when he is told he has two years to live, and follows them as they overcome the obstacles of his illness, through their lengthy marriage and his international fame.
Redmayne met Hawking just days before filming and worried the meeting would undermine his preparation. But instead it gave him exactly what he needed.
"What I took away from the experience of meeting him was his razor-sharp wit, his capacity not to miss a beat," Redmayne said. "He sees everything. He controls a room. He has a formidable power, like a sense. He emanates strength."
Director James Marsh saw a parallel between the film and his 2008 documentary "Man on Wire," about high-wire artist Philippe Petit's walk between the twin towers of New York's World Trade Center in 1974, and knew casting was crucial.
"If you made the wrong choice, or even slightly the wrong choice, the film wasn't going to work," Marsh said.
Both films, he added, were about transcending expectations of what a person can and cannot do. For Petit it was that event and for Hawking it was his daily struggle.
"Both are uniquely gifted human beings who have to do something that is beyond most of our ability to do," he said.
The same might be said of Redmayne, who critics say is a safe bet for a best actor Oscar nomination for a performance that The Telegraph newspaper of London called so good "you temporarily forget he's acting."
Although Redmayne is flattered, he said his most satisfying experience was after Hawking, 72, had seen the film and said that at times it felt like he was watching himself.
"It was a truly amazing performance," said Marsh. "The riches of that performance are not in the technicalities. They are in the emotional life of the character that he projects with all this in place."
(Editing by Mary Milliken and James Dalgleish)