How the Prisoner of Azkaban became the ‘dark’ Harry Potter film we know today

2004’s adaptation of Harry Potter and the Prisoner of Azkaban faced some big challenges.

Chris Columbus, who had directed the first two films, was moving on. Richard Harris, who had originally played Professor Dumbledore, had died just before the second movie’s release and was replaced by Michael Gambon. But more than anything, author JK Rowling’s original novel saw a sharp tonal shift from pure family adventure to teenagedom and much more shade than light.

It was a change new director Alfonso Cuarón, and cinematographer Michael Seresin (War for the Planet of the Apes, Mowgli, Bugsy Malone), embraced from the off.

"It was a pretty definitive film in terms of having such a different director and working style," Seresin, who made his name in Hollywood as Alan Parker’s go-to director of photography, tells Yahoo 20 years on from the film's original release.

"It was very different for me and for [Alfonso Cuarón] too, because he'd worked mostly, if not exclusively, with one cinematographer who he went to film school with."

Read more: How Michael Gambon made Dumbledore his own

Cuarón had impressed Hollywood with A Little Princess and then made one of the best Spanish-language movies in Y Tu Mamá También, but when he was initially approached, he hadn’t even read the books before being embarrassed into it by his friend Guillermo del Toro.

Seresin too admits he didn’t watch either of the previous instalments (and still hasn’t) so he wasn’t subconsciously influenced by their aesthetic. But the pair had a strong rapport and knew what they wanted to do.

"It was a conscious decision to make it, where it was appropriate, quite dark and moody. It's a dark story, but also both he and I gravitate towards the dark side in some ways, cinematically," Seresin says. "In darkness and shadows, you engage an audience. They can't see everything always and their imagination comes to life, they interpret stuff often quite differently. I like that."

Was there not any concern about it being a big family blockbuster?

"In a way we probably didn't think we were making a kids’ film, even though kids are the stars of the movie," he continues. "There was a lot of darkness happening in [the characters’] lives. I’ve only ever heard positive things about the scariness of it."

Never work with kids… unless you’re Alfonso Cuaron

One thing the first two films had come under some pressure for was the acting of the stars, who captured the essence of Rowling’s creations, but were still finding their footing on-screen. Prisoner of Azkaban transformed that, by getting the best performances to date from Daniel Radcliffe, Emma Watson and Rupert Grint.

"[Cuarón] gets on super well with children in life and in cinema," explains Seresin. "Almost preferring them to adults at times. Socially, we’d see one another when our kids were super young and we’d go to a park and he'd hang out with the kids more than with the adults.

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"Occasionally I’d listen to Alfonso talking to the kids after rehearsal and he'd say something to one or two or all three of them and you could see the change in their performance, which is one of the biggest signs of a kid understanding what's required of them for the part," he continues. "And they were very articulate, particularly Emma. They did sort of mature between two and three."

A massive undertaking

He may have worked on two films in the Planet of the Apes’ reboot series, but for Seresin, Harry Potter remains the biggest film he’s worked on.

"I don't think the word franchise was used much then," he says. "They said, 'oh, we've got to go to Scotland in May, because it never rains, you know, historically.' So we went up to Scotland for a month, six weeks and literally apart from day one, it p***ed with rain every day."

"We built some quite big sets up there, up on the hills, which you probably didn't need to do. We could have done it with just tiny bits and green screen, but maybe with the wind and the rain and dragging it half a mile up a massive hill, it would have been just impractical. It was tough enough as it was."

He and Cuarón decided to shoot it differently to how it had been done on Philosopher’s Stone and Chamber of Secrets.

"We worked very much in a pyramid sort of way. Alfonso at the top, me alongside him and then we oversaw every unit. We had second unit, we had model unit and I had to see all the dailies high speed every morning to okay not just what we did, which we were pretty happy with, but also the other units.

"Occasionally I'd see something which I felt didn't fit in with our stuff, which it had to, like Harry flying through the air or a double or something like that. Mostly we did it with one camera, whereas the other ones, they had like half a dozen cameras shooting everything. And I've never worked like that."

This method meant they were able to achieve some brilliant things. Seresin remembers in particular the scene where Harry and Hermione are working the Time-Turner.

"It was a Steadicam shot with a 180-degree movement," he recalls. "And there's a lot of stuff going on in the background, which the second unit was about to shoot. Time was going backwards. And then Alfonso says, ‘Let's make it a 360’. I said, ‘You’re not serious. What would [your usual cinematographer Emmanuel Lubezski] say to you? He said, ‘Tell me to f*** off probably.’"

Seresin instead took some time and made it work.

"And funnily enough, that's where director’s intuition is so right," he admits. "There was no cut and it didn't look tricksy. I remember looking at it when it was all put together and thinking, Jesus Christ, that is magic. The combination of all the elements of filmmaking from shooting it, the performances, the shots and then marrying it with CGI and looking down into the courtyard and seeing the kids there was absolutely magical."

The legacy of Prisoner of Azkaban

Harry Potter and the Prisoner of Azkaban was released on 31 May 2004 in the UK and while die-hards Potter fans initially criticised it for excising so much of the book, it is since generally recognised as the best episode in the saga.

"We were on a flight coming back from New Zealand and four films I shot were on there," laughs Seresin now. "There was Prisoner of Azkaban, one of the Apes movies and a couple of others."

Read more: Why did Harry Potter never win any Oscars?

But the cinematographer’s spell in the Potterverse remains a fond moviemaking memory.

"My kid was eight or nine when he came to the premiere and he was sitting behind [Daniel Radcliffe]," Seresin says. “There's a scene where somebody sneaks up on Harry and my son’s going, saying, ‘Duck! Duck, why didn't you duck?’ And there's [Daniel] sitting in front of him, saying, ‘Yeah, I should have, you're right!’"

Harry Potter and the Prisoner of Azkaban is returning to UK cinemas on 31 May.