That was about this kid finding his identity as a teenager and the feeling that this kid is learning both that fears and the power to fight reside within, so once we went into that line it was very easy to discriminate which of the multiple elements that play in the book, which ones would be relevant to this theme. We concentrated on one theme, because what we wanted was a movie that was character-oriented with special effects, rather than to be a special effect film with a bunch of characters.

They knew all the technical aspects of doing a film with special effects. So they knew about marks, they knew about little strings, they knew about performing against a little tennis ball that later on is going to become a CG character. There's a bigger awareness of what they're doing when they're thirteen. So an eleven year old can be something fun and cool and that's make believe. These kids are thirteen. After working, they've been very lucky to work with some of the best actors alive in number one and number two. So they wanted to start taking a little more seriously their craft and they were willing then to explore emotional territories they hadn't explored before.

"Okay, how would you wear your uniform?" First, they were all "Oh, tie does this." I said, "Yes, but if your parents were not around!" Then they started doing weird things with their ties or taking their shirts out, some of the kids tucking everything in trying to be very neat, and I think that comes through in the film.

The hairstyle was pretty much dictated by the kids. I mean, obviously we knew that Harry Potter had to have a little rebel hair. The hair is coming, you know, how the hair is, is sticking out, so I said, "Okay, we're going to stick him out, do a little longer here." But Dan was through the process of doing different tests with the hair and said, "Okay, yeah, it's more like that."

Emma (Thompson -- Prof Trelawney) is so much fun. The thing with Emma is that she just keeps on trying. I'm so pleased that whenever people see that scene - those two scenes - it's so much fun, so eccentric, so coo-coo. There's a moment that is very funny and coo-coo that goes into a very scary mode, and that's great.

One shot connecting with another one, rather than working with coverage. I wanted to really, as if the camera comes and says "Okay, give me your hand" and the camera just takes you through the whole ride from the first frame to the last frame.

Alfonso was keen to explore in the film and which he discussed with me at the outset was this notion that when you become a teenager, or as you grow up, the demons are no longer just the monsters in the closet, the basilisk, the giant spiders and the likes, but actually the demons begin to come from within and a lot of the darkness comes from within.

Dumbledore is who Dumbledore is by the very nature of what Jo Rowling wrote - wise, eccentric, with a twinkle in his eye, and I think Michael has all those qualities.

I think it's interesting to see Harry dealing with that sense of rebellion. He's not going to take it anymore, he is not going to put up with the rules Uncle Vernon has sort of set in stone in the house.

There was a line that was cut from the script that I loved, when Harry said to Uncle Vernon, "I'm tired of living by other people's rules." And I thought that was the heart of the film, I thought that, that's exactly what it means to be a teenager. You know, it's like those great rock 'n' roll songs from the sixties - "it's my life, you can't tell me what to do."

When he walks out of the Dursley house at the beginning of the movie, that's pretty powerful. The fact that he's taken a stand and he's walking away from this nonsense. You realize that you're in a different world now, these aren't kids anymore.

What's wonderful about watching this film is that there are a lot of moments where we don't cut away from anything. We're actually staying with the actors, which is something we couldn't do in the past.

One of the most moving and emotional sequences is Harry riding Buckbeak through the grounds of Hogwarts. I just think that's a lyrical, poetic moment that just is, is very moving.

You know before, we never really had the opportunity really to rehearse and they pretty much came in and they would do you know what you would ask them to do and they did a terrific job. They were very concerned why they were doing certain things and what the reaction would be.

He (Alfonso) is as concerned about the highlight on the rock which is next to the Whomping Willow as he is with does it match also the light coming in from the hillside behind the trees, which you barely really even see. I mean he is, "Are the shadows really projected, are we getting strength of the shadows?" You sat and you listened to this, but when you see everything composited together it is amazing the impact that it has, and the strength of the shot. I mean, the visuals are stunning.