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 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 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.

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.

With Dustin Hoffman, I just enjoyed the fact he was this flamboyent and very ironic person that still followed my desire to make Baldini in the Perfume: The Story Of A Murderer not simply a joke, or the funny guy, but also a personality and a character.

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.

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.