10/09/2011 02:23 pm ET Updated Dec 06, 2017

'My Week With Marilyn': Michelle Williams Is A Revelation As Marilyn Monroe

"My Week with Marilyn," the Marilyn Monroe biopic starring Michelle Williams as the screen legend, had its world premiere at the New York Film Festival Sunday. The film, directed by Simon Curtis, is based on a memoir by British filmmaker Colin Clark, "The Prince, the Showgirl and Me." Clark was an assistant on the set of Sir Laurence Olivier's "The Prince and the Showgirl" and, as the title suggests, had a brief affair with Monroe, who was married to Arthur Miller at the time.

Though Clark's perspective (played by Eddie Redmayne) is necessarily the filter through which to see Monroe, he comes off too much the earnest young gofer, and the movie feels downright Disney at times as a result. That said, Williams is a revelation and brings a much-needed darkness to "My Week with Marilyn." She isn't the spitting image of Monroe, but she manages to inhabit her shades without overdoing the coquettishness or underplaying the tragic vulnerability. Among a high-profile British cast -- the solid (Kenneth Branagh, Judi Dench) and the not-so-solid (Emma Watson, we wish you were better!) -- Williams is clearly the best thing about this movie, and a shoe-in for an Oscar nomination.

In a press conference following the screening, Williams explained how she approached a role that could have easily been mishandled.

"It was just something that I put on in my living room [so I] didn't feel the repercussions," Williams said. "It was very self-conscious. It all started at home, watching movies, listening to interviews."

Her first breakthrough was discovering that Monroe herself was a character.

"It was carefully honed, but it was artifice, but it was honed so you couldn't tell it was artifice -- it felt so real," Williams said. "It was something that she'd studied and perfected and crafted."

Williams essentially plays three Marilyns in the film -- the private Marilyn, the public Marilyn, and the Marilyn in "The Prince and the Showgirl." But she said it doesn't help much for her to think of the role in such a disjointed way.

"You have to think of them together because it needs to adhere," she said. Achieving this cohesiveness, however, didn't come easily.

"It was a long and ungainly process," she said.

At one point during the Q&A, a man in the audience mentioned that he'd studied under acting coach Lee Strasberg with Monroe and had gotten to know the star a bit. He was stunned by Williams' portrayal, who he emphasized had captured her "perfectly." Williams, who was otherwise soft-spoken and reserved throughout the conference, immediately lit up, smiling appreciatively. There was a hint of the Marilyn in Williams at that moment, who, throughout the film, would glow with every word of validation.

"My Week with Marilyn" is in theaters Nov. 4.

Check out photos from the press conference following the premiere of "My Week with Marilyn":