Sir Ian McKellen isn't the first person you'd think of to play Sherlock Holmes, currently incarnated on TV by brainy Benedict Cumberbatch and in movies by action-man Robert Downey Jr., but Mitch Cullin's novel A Slight Trick of the Mind centres on a 93-year-old Sherlock, and it has been made into the film Mr Holmes starring the 76-year-old McKellen.

Ian McKellen in Mr HolmesIan McKellen compares playing Holmes to playing Hamlet

"I needed more make-up to look 60 than I do to look 93," says McKellen of the two time periods depicted on-screen. But he wasn't worried about taking on such a venerable icon. "I mean, I played Hamlet. If you started thinking about all the people who've played Hamlet, you'd never step onto the stage."

More: Read our review of 'Mr. Holmes'

He also feels that this is a different take on the character, and not just because he's feeling his age. "There have been 150 films about Holmes, apparently," he says. "That's a lot, but it shows that this is a character that people are endlessly fascinated by. The take of this film is that he wasn't fiction. He was a real man and he wasn't really like the Sherlock Holmes that Dr Watson portrays in the short stories and novels."

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And he especially liked the fact that this movie shows a different side to the character that we've never really seen before, "that someone we think we know well turns out to have a beating heart that he's trying to catch up with and has spent 30 years running away from," McKellen says. "I found it very touching that in what's clearly the end of his life, he wanted to complete the emotional side of his life that had been neglected, and he's a much nicer person at the end than he was at the beginning. So there's hope for us all, I suppose!"