The most important thing is that you have to have the visual effects working for you, instead of you working for the visual effects.

But there's something about the simplicity of Auschwitz... there's just nothing. There's just photographs, there's a room full of limbs, a room full of hair, and then you go into the place where the gas chambers were. You walk down these halls and the efficiency of it is so inhuman. The place is so powerful, just for its utter bald, bare simplicity.

I like stories that begin with characters. I like to be engaged and moved by the characters in the story. I want to be moved. I want to leave the cinema and think about what I've seen. My sensibility is quite eclectic and it doesn't matter if they are small or large films, I just want to make good films.

Making the films is never easy, but actually that aspect of trying to make a better film or to keep the standard high is something that comes organically.

I'm interested in making films of all sizes. During this time I've made a film called 'The Boy in the Striped Pajamas', which is a modest-sized film. I was involved in 'I Am Legend' and 'Yes, Man', but 'Potter' is unique. There'll never be anything like 'Potter' again.

Because actually it's really hard to get things made. It takes years. To fight the fights you inevitably have to fight, even when you've produced Harry Potter, you'd better have the commitment and the passion to knock down walls, not take no for an answer.

A lot of things change and a lot of things stay the same, they mostly stay the same.