<P> Cuarón originally wanted to move away from CGI toward puppetry . He hired master underwater puppeteer Basil Twist to help, using puppets to study the potential movement of the Dementors . Once it became apparent that puppetry would be too expensive and unable to portray the specific elements of the Dementors, Cuarón turned to CGI; however, he and his team did use footage of Dementor puppets underwater as a basis for the flowing movements of the computer - generated Dementors . </P> <P> The Knight Bus segment when Harry is being taken to The Leaky Cauldron uses the technique known as bullet time, popularised in The Matrix series of films . This segment takes humorous advantage of the magic quality of the Harry Potter world by having the Muggle world go into bullet time while inside the Knight Bus, Harry, Stan Shunpike and Ernie Prang (and the talking shrunken head) keep moving in real time . </P> <P> The Academy Award - nominated score was the third and final score in the series to be composed and conducted by John Williams . It was released on CD on 25 May 2004 . In general, this film's music is not as bright as that of the previous films, with distinct medieval influences in the instrumentation . One of the new themes, "Double Trouble," was written during production so that a children's choir could perform it in Hogwarts's Great Hall in one of the film's earlier scenes . The lyrics of "Double Trouble" are from a ritual performed by the Weïrd Sisters in Act 4, Scene 1 of Shakespeare's Macbeth . The film's trailer prominently features the cues "Anticipation" and "Progeny" by Brand X Music, a trailer music band . </P> <P> Prisoner of Azkaban was, at the time of publication, the series' longest book . The increasing plot complexity necessitated a looser adaptation of the book's finer plot lines and back - story . The film opens with Harry using magic to light his wand in short bursts, whereas in the same scene in the book, he uses a torch / flashlight, as performing magic outside the wizard world is illegal for wizards under the age of seventeen . The connection between Harry's parents and the Marauder's Map is only briefly mentioned, as is Remus Lupin's association to both the map and James Potter . Additionally, it was never mentioned who the Marauders were or who the nicknames Moony, Wormtail, Padfoot, and Prongs referred to . Some exposition was removed for dramatic effect: both the Shrieking Shack and Scabbers the rat are mentioned only very briefly in the film, while they receive a more thorough coverage in the novel . Most of Sirius Black's back story is also cut, with no mention of the manner of his escape from Azkaban . Only the first Quidditch game was kept in the film, due to its importance to the storyline; the second (Gryffindor / Ravenclaw) and third (Gryffindor / Slytherin) were cut . Thus, Harry receives the Firebolt at the film's end, while in the book he receives it anonymously at Christmas and it is confiscated for a few weeks to be checked for possible jinxes by Professor Flitwick and Madam Hooch . </P>

Harry potter and the prisoner of azkaban extended runtime