The films you're making have to be faithful to the material.

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.

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.

In some ways, many of the skills you have as a producer on independent films also apply to making big tentpole films: You surround yourself with a brilliant director, great script and talented people in every department who are smarter than you.

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.

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.