They know you're not Alfred Hitchcock, but you need to be enough Alfred Hitchcock for them not to be bothered by it. That's a reassuring thing.

I had to change the shape of my own voice. It was quite hard to pull off and so once I had it, I stayed in Hitchcock's voice all day on set.

I think it will be, as always, interesting to compare different portrayals of Hitchcock. I'm very honored that I'm playing the same part as Anthony Hopkins.

Hitchcock is a big ask. I am playing someone significantly older than me and someone significantly bigger than me. The stuff I find very interesting is why certain physical things have come about. How can he be light on his feet when he is so big? How can his weight vary so much? Where does this rather beautiful voice come from?

But I think the children of actors share a certain pragmatic approach. One is denied some of that 'running away with the circus' element of being an actor.

I'm very fortunate that I get asked to do very different kinds of roles and I realize how much I enjoy that. I enjoy the challenge of transformation. There are actors who play one character, or a certain kind of character, the whole of their lives. I really relish the opportunity to have the challenge to totally transform.

Somewhere the glamour has gone because of the industrialization of this whole process. I wish it [filming] felt as magical and glamorous as people want it to be, but it feels like a routine people are going through.