I wanted to create a believable feeling for 18th Century reality in the Perfume: The Story Of A Murderer. I didn't want this typical film feel of strange people in strange costumes, not really knowing what to do or how to move. If you put an 18th Century costume on Alan Rickman, it looks like he's been wearing it forever because he inhabits the stuff. He is a character that can really travel in time as an actor and transform into this 18th Century person with seemingly no effort.

I saw Ben Whishaw playing Hamlet at the Old Vic and straight away had a very strong sense that he might be the end of a very, very long road of searching for the right guy. He did an amazing audition, where it all came across this, instinctive feeling that he obviously had for the character in the Perfume: The Story Of A Murderer.

I think ultimately one would say that the most difficult part of the Perfume: The Story Of A Murderer is the balancing of the main character. To get him being so ambivalent in his whole conception.

I actually met a producer of Stanley Kubrick's who told me that Kubrick had never even thought about doing Perfume: The Story Of A Murderer. He just read it and didn't want to do it - that's it. There's a myth around that he said it's not filmable. But he never wanted to film it.

I was lucky I guess. My main job was done when I finally found Ben Whishaw and knew that there was someone who could portray a character who was so ambiguous and multi-faceted. Ben is equally dark and innocent; potentially violent and yet at the same time kind of a boy. He got all that across and still makes audiences root for the guy even though they might be kind of disturbed by that fact.

If you then cast a somebody, playing a nobody is always an additional effort. But that was not the reason we cast him. It was because Ben Whishaw delivered exactly what I was hoping for.

Alan Rickman has a huge presence in the Perfume: The Story Of A Murderer and takes an enormous amount of space with no effort. I wanted somebody to leave behind a strong impact and be a threat for Grenouille. When Alan takes to the screen, we immediately know there's an intelligent, instinctive and powerful force, so if he's pursuing our main guy then our main guy is in trouble.