Actress Cate Blanchett - who has won an Oscar for her performance as Hollywood legend Katharine Hepburn in The Aviator - nearly turned down the acclaimed role.
The Aviator is Blanchett's second Oscar nomination
Blanchett was the favourite to win the Oscar on Sunday night, for her portrayal of screen idol Hepburn - who until 2003 held the record for most Oscar nominations for an individual actor.
"I think when someone asks you to play Hepburn, you just run in the other direction," Blanchett told BBC Radio 4's The Film Programme.
"It's verging on an impossible task, because she is so iconic."
The Aviator sees Blanchett starring opposite Leonardo DiCaprio, who plays Howard Hughes, and details Hepburn and Hughes' romance and messy break-up.
Blanchett said she was only persuaded to take the role because she was asked personally by the film's director, Martin Scorsese.
"You can't say no to Scorsese," she added.
"And because one's frightened of something is probably the reason to do it - because you can but fail.
"If you do fail it's a very public failure, but if you don't take the risk, you don't have the adventure of it."
She added that Scorsese was not so much interested in having an actress who could mimic Hepburn as much as someone who could "unlock the spirit of the woman".
Blanchett is also starring in The Life Aquatic With Steve Zissou, in which she plays a journalist following an expedition, led by Bill Murray's eponymous Zissou, on the trail of a giant - and possibly mythical - shark.
The Life Aquatic is the fourth film from director Wes Anderson, who is noted for his quirky, offbeat comedies such as Rushmore and The Royal Tenebaums.
"The great thing about working with someone like Wes Anderson is he's a real auteur," Blanchett said.
"He's a very polite person - he's quite English, in that clichéd way... there's a restraint to him.
"It's not that things aren't twisted, because he places characters in unusual situations - but they're always believable because there's an earnestness to the characters - they take themselves incredibly seriously."
Blanchett's diverse film choices are indicative of her versatility as an actress.
Other biographical roles include her Oscar-nominated turn as Queen Elizabeth I and portraying Irish journalist Veronica Guerin.
The Life Aquatic sees Blanchett verbally sparring with Bill Murray
But she has also starred in literary adaptations such as Charlotte Gray and The Shipping News, and the popular Lord Of The Rings trilogy.
For Blanchett, the most important thing is that the audience finds her credible.
"Always, whether you're playing a fictional character or someone who lived, it is an active invention, because you have to tell the story, play the character that's been described in the script, and try to feed as much detail as you can," she said.
"But how many biographies are accurate? Often they're more about the biographer than the subject.
"So, somewhere between all those things that you're filtering through, will lie the particular truth that's being described in the film."