Batman star Christian Bale struggled at first with his portrayal of the Caped Crusader - because he found it hard to adopt the superhero's trademark gruff voice.
The actor insists that when he first took on the role for 2005's Batman Begins, mastering the character's deep tones was a real challenge.
But now, with second movie The Dark Knight completed, he can effortlessly slip in to character Bruce Wayne's voice.
He says, "On the first film, it took me a while to really get accustomed to the voice but it's like riding a bike.
"For the second one, I could just switch on and off any time."