Warning: This post is Spoiler-ific in the extreme. If you haven't read the Potter books and intend to, don't read it. If you haven't seen the latest film (HP and the Half-Blood Prince) and intend to, don't read it. That said, if you don't know who dies at the end of HP6, you've been living under a rock and need to get out more.
I am utterly fascinated by the Harry Potter films. It's not so much the films themselves - although they are, generally, rollicking good fun - but the way the books are translated to the screen that fascinate me. And I mean translated, not adapted; films and novels are such different languages.
The catch here is, of course, that the films began pre-production before all the books were out. I read somewhere, a long time ago, that JK Rowling was keeping an eye on the films, making sure that certain details or certain characters weren't cut, if they had great importance to later plot points. (Also, apparently Alan Rickman was given Snape's backstory and knowledge of his ultimate allegiance before book seven came out.) Still, small things that are planted in the book (Harry sees Ravenclaw's diadem in the Room of Requirement when hiding his potions book in book six) are left out of the films. So even if the details are right, because of the constraints of film, some richness is necessarily left out (for example, Bill and Fleur's relationship.) Other plots are almost entirely changed; in the book, Ginny and Dean break up with the help of Harry's luck potion, while in the film, it's pretty arbitrary. The film's handling of the Hermione/Ron romance is different, as well; I don't recall in the book that there was any real option of them getting together, between their distractions with Voldy and exams, and Ron's general Ron-ness, and they really only get together in the last book after Ron proves himself worthy of her with his concern for the house elves.
But the biggest change was that odd, exhilarating, creepy scene where Bellatrix and Greyback attack and burn down the Burrow. Devastating, yes, and I understand that Hollywood felt the need to insert some action into a fairly plotless film, but, it doesn't make sense in the world that Rowling so painstakingly created. One: we know that Dumbledore has put extra protections on the Burrow while Harry is there. Two: how do the bad guys know where he is? Three: Uh, Voldy has made it crystal clear that he himself wants to kill Harry. Four: How did they succeed in not hurting anyone else? Five: Um, Ginny is a MORE than competent witch at this point - why is she screaming helplessly for Harry? Her running into the field to help fight, that is perfectly Ginny-like. Her then losing courage? Not so much. Also, why the heck didn't they just put out the fire with water? Or was it that super-fire spell, the uncontainable fire that destroys the diadem in book seven?
Anyway, as Tasha Robinson said so astutely in the
AV Club podcast about the film, the film is really about a mood. And part of that mood is the sense of impending doom, of death lurking around the corner; maybe a bit of actual destruction is necessary. And while, as my friend Nancy pointed out, the CGI stuff kind of overwhelms the coziness and intimacy of Hogwarts this time round, I think that was part of the point - the world is encroaching, even on Hogwarts, and the golden, cozy light is only in evidence when romantic things are happening (Rupert Grint is absolutely brilliant as Ron under the influence of a love potion). Everywhere else, even in Quidditch, it's grey and gloomy.
I remain in thrall; I can't wait to see how they handle the last two films (the last book is split into two films.) I can hazard a guess as to where they'll split the films (just after Ron leaves the trio, I bet) and I'm glad that they actually know everything going into the writing of these final scripts. All in all, I think they've done a fine job of an overwhelming task.