So what really happened on the Harry Potter set...

Bob Calder author of Harry Potter Page To Screen: The Complete Filmmaking Journey got to go where other writers could only dream... behind-the-scenes on the Harry Potter set!

The book is packed with information and pictures (check out some of the pics HERE) about everything that happened on set and discusses how every single book, scene, character and prop was brought to life for the screen. Oh the things Bob must have seen - we just had to pick his brain about it all.

Read our Q&A with him below to find out which stunt went dangerously wrong, the letters JK Rowling wrote to many of the cast and just how upset Emma Watson got on the last day...

© 2011 Warner Bros. Entertainment Inc.

What was the most surprising thing you uncovered when researching for the book?
One of the most impressive things was how normal everyone was. The whole Potter production – all ten years of it – has largely been based in a relatively remote location – Leavesden Studios, where there isn’t much else  around. As a result, everyone has found themselves stuck there, making the bets of the situation. And due to the producers keeping an eye on their young cast, everyone has had to balance movies, stardom and glamour with the realities of school and work.

Thankfully, everyone seems to have kept their feet on the ground. There were no egos, no one unwilling to talk for the book, no one who didn’t simply want to help. And, thankfully, no one just back from rehab.
What do you think was the biggest challenge creative team faced?

I think the biggest challenge the filmmakers faced over the eight films was allowing the films to grow up in the same way the books had done. Rowling’s great achievement for me was writing a series of books that allowed her readers to grow with them – you could read the first one at the age of ten and you’d still be there at 18 waiting to see how it all ended, which is unique. But also something of a gamble.

The movies had to allow for the fact that the final film was going to be a lot tougher and darker than the first. There’s always a tendency in movies to try and not lose your audience, but in a way the Potter movies had to grow.  You can watch any of the Star Wars movies at any age – but I wouldn’t let an eight year old watch the last couple of Potters. That was a brave move and, of course, the right thing to do.

How heavily involved was J.K Rowling in the envisioning of the film?
JK always wanted to keep the two things separate – HER books, THEIR films. That said, she was involved from day one making sure they got it right, and continued to be an advisory presence throughout. But I feel that once she realised she had the right people in place, from producer David Heyman on down, she was confident enough to let them get on with it, knowing that they felt as passionately about her work as she did. In the early stages of each movie, she would provide insight for the filmmakers, especially when they were unsure of what was going to come in the next book. And to the young cast she was a figure they could turn to on occasion. Many of them fondly recalled the personal letters they unexpectedly received from her, telling them how they’d brought things to life just as she had originally imagined them. Treasured items for all.

Did you spend time during cast with the filming - what was it like watching them film?
I was around the set for around the last nine months of filming. Sadly, the reality of filmmaking is the old cliché that for the most part it’s incredibly boring, no matter how magical the movie. Lots of down time, as everyone waits for the next shot to be set up, to perform generally only a fraction of a scene, then to repeat it several times, and then often to come back to another part of that scene several weeks later. There’s a lot of hanging around.

That said, most of the cast have grown up doing just that, so they’ve worked out how to cope. Dan and Rupert had the best rooms – complete with plasmas, X boxes, guitars, drums and table tennis. When needed back on set, they were ferried in on golf buggies and always right back into their performances.

Who had to spend longest in makeup?
Of the main cast, Warwick Davis seemed to have the hardest job, being transformed into either Flitwick or Griphook took the best part of three hours a day, which meant a very early start for Warwick. Dave Legano also had a hairy time as Fenrir Greyback, which involved not only a new chest, but all the hairs on his face been woven in one by one. As for the young cast, they only really had it bad on the last two movies, where various battle scars and cuts had to be added.

Click NEXT for more Q&A and to find out what the MOST dangerous stunt was...