Hero Fiennes-Tiffin was cast as Tom Riddle, Age 11, while his uncle, Ralph Fiennes plays Lord Voldemort (formerly Tom Riddle). His parents are Martha Fiennes (Ralph's sister) and George Tiffin. Director David Yates says that he hired Hero because of his resemblance to his uncle, but not specifically because he was the actor's nephew. He liked the dark haunted quality about the young actor.
Although all the teachers at Hogwarts are addressed as "Professor", J.K. Rowling has said that there is no university for wizards. This revelation has two implications: first, that the professor salutation is an honorific; second, that those who wish to learn more than standard schooling must apprentice themselves to experts in any given field, just as was done in the Middle Ages.
Horace Slughorn's outfits were designed to look very rich and elegant, but also old and threadbare. The costumes were distressed to make them appear worn, and in addition, were washed in a powdery solution to make them appear as if they had gathered dust during the years of Slughorn's retirement.
Three new scenes were added that do not appear in the book: The collapsing Millennium bridge (at the beginning of the film, and which appears in the Third Trailer); Harry flirting with the waitress at the underground station before meeting up with Dumbledore; and the Death Eater attack at the Burrow (seen in the second trailer). An attack on a Muggle bridge is actually mentioned in the original opening of the book by Cornelius Fudge, but in an after the fact manner.
Over 7,000 girls auditioned for the role of Lavender Brown, and read from a scene with Madam Pomfrey, Hermione, and Ron. Ironically, Emma Watson recommended Jessie Cave for the role, which she got, even though she hadn't attended any of those auditions.
Horace Slughorn's appearance in the film differs dramatically from his description in the book, possibly more than any other character. In the book, he is described as being extremely fat and bald, with a "walrus-like" mustache. In the film, he is depicted as being only slightly overweight, his hair is only slightly thinning, and he doesn't sport any facial hair at all. However, his character is quite similar: although Slughorn is depicted as somewhat shrewd and opportunistic, in both the book and film, he is a friendly man, who breaks with the traditional character of Slytherins being cold and unsympathetic.
As an homage to J.K. Rowling, Stephen King, a fan of hers, included a reference to the series in his novel 'Wolves of Calla', featuring Snitches as flying grenades. 'Wolves' was published one year before the 'Half-Blood Prince' novel. Rowling, in turn, returned the favor: the Gaunts (Voldemort's maternal family, though Dumbledore did not mention in the film) is alluded to Leland Gaunt - the lead antagonist in King's novel 'Needful Things' (played by Max von Sydow in Needful Things (1993)).
Professor Slughorn says that he taught the entire Black family, except for Sirius. As Hogwarts only has one teacher for each subject, it may seem a bit odd that he would not have taught Sirius. The book explains this differently, however. In addition to teaching Potions, Slughorn was also head of Slytherin House, where all of the Blacks were sorted, except for Sirius. So while Slughorn taught Sirius, he never had him in Slytherin.
Production designer Stuart Craig revealed that the Three Broomsticks' design was constructed for the Wizarding World of Harry Potter theme park first. Subsequently, the film crew constructed an exact replica during filming.
The night scenes were filmed in the quaint village of Lacock and the cloisters at Lacock Abbey for three nights, October 25-28, 2007. Filming took place from 5 P.M.-5 A.M., and residents of the street were asked to black out their windows with dark blinds.
The original script included all of Dumbledore's memories about Voldemort, as outlined in the source novel, but David Yates insisted on trimming them down as, according to Steve Kloves, "..he wanted to showcase Voldemort's rise without getting overly involved with his past as Riddle."
Many fans have expressed distaste in the fact that Harry is shown at a train station, saying it would make more sense for him to be at the Dursley's. This is actually a nod to the book, because Harry said he liked riding trains, that it "helped him take his mind off things."
Tim Alexander described Dumbledore's ring of fire as "someone sprayed propane and then lit it." Then, to enhance the effect, the visual effects team spent a lot of research on molten volcanoes (which have a lot of heat but no actual flames), and other references, including flares that burn underwater. The whole fire scene was very time consuming, with computer graphics artist Christopher Horvath spending eight months on it.
Wanting to bring a different look to this film, David Yates chose French Cinematographer Bruno Delbonnel, known for his use of stylized color palettes that often feature prominent earthy tones. At first the film was extensively color graded, and due to the overly dark tones, Warner Bros. asked Yates and Delbonnel to add more colors to the film, as they could barely see a thing on screen. Both Yates and Delbonnel were hesitant to do this at first, but after retouching some of the scenes, Delbonnel realized that he had overused the grading and the final product was better. Yates remarked Delbonnel's work on the film as "The choice of angles, the extreme close-ups, the pacing of the scenes...It's very layered, incredibly rich." It was the first (and ultimately, only) film in the Harry Potter series to be nominated for a Cinematography Oscar.
Some fans expressed distaste that Slughorn played favorites with students, but J.K. Rowling explained it differently. Professor Slughorn is a meritocratic teacher. He shows interest and appreciation towards those who are smart, capable, and well-connected. If a student wishes to gain attention, then they need to excel in their work. By being choosy with his favors, Slughorn spurs all his students to try harder.
Like many of the fashions at Hogwarts, Professor Slughorn's mortarboard cap has a rich history. It was used in the 14th and 15th centuries to identify humanists, students, artists, and the learned in general. Slughorn's tassel is black, signifying an advanced degree.
At the beginning of the film, the Death Eaters destroy the Millennium Bridge in London. In the book, it is actually the Brockdale Bridge that is destroyed. The book is set in 1996-1997, according to the canon time line. The Millennium Bridge was not constructed until 1998, and opened on June 10, 2000.
Much like the first book, some differences exist between the British and American editions of the text. One such difference is in the scene where Dumbledore takes Harry to meet Slughorn. In the American edition of the book, Dumbledore excuses himself to use the bathroom. In the film, he uses the more British term, "loo." This is in contrast to Harry Potter and the Sorcerer's Stone (2001), in which such references were shot twice to accommodate American and British audiences.
Even though they feature in the beginning of the book, the Dursley's do not appear in this movie. This is the second film they have been left out of, with the first being Harry Potter and the Goblet of Fire (2005)
According to Stuart Craig, Tom Riddle's orphanage is based on buildings from the Liverpool Docklands, and it is influenced by Victorian-Georgian architecture. In fact, the orphanage's exterior uses original Victorian glaze bricks, to give the set a very hard structure.
Originally to be released on November 21, 2008, the studio decided to postpone it to July 15, 2009. Officially, the decision, according to studio chief Alan Horn was largely due to the writer's strike at that time, but unofficially, and known to most, the decision was following the massive earnings made by another studio movie, The Dark Knight (2008) that released on that week of July. With that, Twilight (2008), which was supposedly to be released on December 12, 2008, moved to fill in that vacant release slot.
Kevin McKidd was offered the role of werewolf Fenrir Greyback, but could not take part, due to his commitments in other projects, including Grey's Anatomy (2005). He has since stated that he was glad he did not to take the role, for his young children would not take kindly to his appearance on screen. Ironically, McKidd once played the lead role in Dog Soldiers (2002), which saw him battling a pack of werewolves.
The tapestry seen near the Room of Requirement is the last of seven in "The Hunt of the Unicorn" (or the "Unicorn Tapestries") series, called "The Unicorn in Captivity." The real tapestry can be found at the Cloisters in New York City.
During the memory scenes involving young Tom Riddle, including the orphanage, the scenery is green, which is one of the colors of Slytherin, which Tom Riddle was sorted into, as he was the last descendent of Salazar Slytherin.
Unlike the book, Harry and Ginny become an item during the Christmas holidays. It was never explained why Ginny and Dean split up in the film, but it is strongly implied they argued a lot as hinted by Hermione during the slug club scene.
This is the second time Tom Felton and Jim Broadbent have worked together. The first time was in The Borrowers (1997), as members of the four-inch tall family; son Peagreen Clock and his father Pod Clock respectively. Also, Mark Williams (Arthur Weasley) played the part of Jeff the Exterminator.
David Yates and the producers asked Wally Pfister if he could do the cinematography for this movie. Pfister declined since The Dark Knight (2008) was shooting at the same time, citing schedule conflicts.
The second film to NOT open with a "Harry-centric" event. Harry Potter and the Goblet of Fire (2005) opened with a scene from a chapter of the fourth book, "The Riddle House". Harry Potter and the Half-Blood Prince (2009) opens with an event which is mentioned in the first chapter of the sixth book, "The Other Minister", where the Death Eaters collapse the Millennium Bridge in London. (Although the first images in this film are of Harry and Dumbledore at the Ministry of Magic after the battle with Voldemort in Harry Potter and the Order of the Phoenix (2007), the first legitimate and complete scene is the Death Eater attack.)
The pensive, in this film, is different from the film version of the Goblet of Fire. The pensive can somehow float in midair, presumably by a Charms spell, and Harry is not seen in the pensive this time, but it can be argued the memories are seen by Harry via first person. Harry, unlike the book version of this film, sees the first two memories without Dumbledore, but it is implied the pair saw Slughorn's true memory together.
Chris Columbus, the director of the first two Harry Potter films, was amazed how beautifully Daniel Radcliffe, Emma Watson, and Rupert Grint matured over the series, compared to some child actors, who start out adorable, and then either lose that, or become bad actors as they grow older.
Advance ticket sales on Fandango.com for the film surpassed advance ticket sales for Transformers: Revenge of the Fallen (2009) at the same point in sale cycles. It is also in MovieTickets.com's top 25 advance sellers of all time.
Regulus Black (Tom Moorcroft), Lily Evans (Susie Shinner) and Lucius Malfoy (Tony Coburn) all were supposed to be among Horace Slughorn's previous favorite students. They were among those in Slughorn's photographs.
Yet another photograph shown to Harry Potter was that of "Daily Prophet" Editor, Barnabas Cuffe (Roger C. Bailey).
Unfortunately, only the backs of the frames were shown. This resulted in deleted scenes for all of the actors.
Robert Hardy (Cornelius Fudge) has an uncredited voice-over at the start of the movie: Immediately after Helena Bonham Carter (Bellatrix Lestesnge)'s line, "I killed Sirius Black!" (from "...Order of the Phoenix"), Hardy/Fudge's last line from the same movie: "He's back!" can be heard.
When Christian Coulson was cast to play a 16 year old Tom Riddle in 'Harry Potter and The Chamber of Secrets', he was actually 23 years old, but in 'Harry Potter and The Half Blood Prince', Frank Dillane, who was 17 at the time, played Tom Riddle, who was a similar age to him.
The trivia items below may give away important plot points.
Dumbledore's fall from the tower filled Alan Rickman with nostalgic glee, as it harkened back to his first hit Die Hard (1988), where his character fell from a tall building. Rickman felt at least "he was on the other end in this film!"
Steve Kloves' script originally used all six flashbacks of Voldemort. In the film, only two were used. Had all of the remaining flashbacks used, it would give more exposition such as how Merope Gaunt met Tom Riddle, Sr. in the 1920s; how young Voldemort tracked down his uncle Morfin in Little Hangleton in 1943, subsequently resulting in the murder of the Riddle family; the origins of Hufflepuff's Cup being a horcrux - which pays off in Harry Potter and the Deathly Hallows: Part 2 (2011); and finally, explaining why the Defense of the Dark Arts job gets jinxed with each teacher lasting no more than one year since 1956 - Dumbledore turned down Riddle's offer to teach.
When Draco Malfoy goes to the Room of Requirement for the final time, you can see the harp that put Fluffy to sleep and the King from the game of chess from Harry Potter and the Sorcerer's Stone (2001).
On December 12, 2009, a special "BD-Live" screening event of the film was held for owners of the movie on Blu-ray, a first of its kind. It allowed people to watch the film on Blu-ray, while listening live to Daniel Radcliffe and David Barron (sitting in for Yates, who was ill) who were watching, and administering the event. There they discussed various aspects of the entire franchise, while the film was showing, and even had some questions from viewers to address. Among the all too few trivia bits on this particular film they revealed during this screening are: - The "Butterbeer" we see the students drinking in this film is actually a well known British fruit drink called J20, with fake foam added on top. However, an official "ButterBeer" is in the making for a planned Harry Potter theme park. - The foam in Ron's mouth in one scene is made of egg white. - Daniel admitted he never tries to go for "real tears" in any such scenes, by advice he got from Kenneth Branagh. Instead he relies on acting and "tricks of the trade" to get the desired effect across. - The strange "fluid" in Dumbledore's Pensive is entirely done with CGI. - That highly torturous fluid in the cave that Dumbledore drinks, was really just some milk thinned down with water and then visually "tweaked" by the CGI department. Barron commented that David Yates and the composer tried "for months" to create a specific "Phoenix song" score which they felt would do its book description justice, for the scene where the bird leaves Hogwarts. Several different things were composed and tested, before they pretty much gave up trying, and settled on this very basic score we now hear at the end of the film.
In the flashback scene, in which Dumbledore visits the young Tom Riddle in the orphanage, a photograph on the wall of Tom's room depicts the same place to which Dumbledore and Harry travel, in search of the third Horcrux (the locket). In the book, it is described as a place where young Tom Riddle once used magic to terrorize his fellow orphans while on a trip (hence the place has special meaning to him). There are also seven rocks on the windowsill, which is the same number of Horcruxes that Tom/Voldemort created.
When Harry, Ron, and Hermione are talking about Dumbledore's age, Ron says "About 150, give or take a few years" and they start laughing as if it was a joke. This is also the exact number that J.K. Rowling provided during an interview. She later officially stated on her website, that Dumbledore was 115 years old at the time of his death.
During the scene in the cave, where Harry has to force Dumbledore to drink the cursed water, Dumbledore can be heard saying "It's my fault! It's all my fault!". It is revealed in Harry Potter and the Deathly Hallows: Part 2 (2011) that Dumbledore's sister died from a stray curse while he and his brother and best friend were dueling; a psychological trauma, for which he has always blamed himself.
Tom Felton has stated in an interview, that in the near end sequence of the film, after Snape kills Dumbledore, and is leading the other Death Eaters out of Hogwarts and through the Great Hall, an accident had occurred on the set a few minutes into the shooting. Before the actors had started filming, Alan Rickman "turned around in this very sinister way and said, 'don't step on my cloak,'" (at the time of which it was unclear to his fellow co-stars if he was joking or not) as David Yates had instructed the other actors that when shooting began, they were to stay close behind Rickman as they followed him without looking at their feet - a difficult task, due to the dragging length of Snape's cloak. As shooting began during the second take, Felton, being the closest person to Rickman in the scene, had accidentally dug his heel into the cloak, causing Rickman's neck to rip back. Felton had reported there was an awkward silence afterward, clear that Rickman was not in a good mood after the accident had occurred. Felton continuously apologized to Rickman afterward, in that Rickman did accept and made a joke of the accident later on.
J.K. Rowling read through the script, and found a line where Dumbledore mentions a girl he had a crush on when he was younger. After reading it, she informed the filmmakers that Dumbledore is in fact gay, and that his only romantic infatuation was with the wizard Grindelwald, whom he later had to defeat in a wizard duel. She later made this information public while promoting the final book, Harry Potter and the Deathly Hallows.
Originally, the shooting script was written so that Harry takes possession of Dumbledore's wand after he is killed. Shortly before filming began, the final book in the series came out, in which Dumbledore's wand, and who possesses it, turn out to be major issues, so the script had to be changed.
When Harry is in Dumbledore's office at the end of the film, a bowl of sherbet lemons can be seen on his desk. In Harry Potter and the Sorcerer's Stone (2001), Dumbledore announced these to be his favorite Muggle candy.
According to ILM visual effects supervisor Tim Alexander, completing the Inferius attack took several months: "It was much bolder and scarier than we imagined that they'd ever go in a Potter movie. David Yates was really cautious of not making this into a zombie movie, so we were constantly trying to figure out how not to make these dead people coming up look like zombies. A lot of it came down to their movement - they don't move fast, but they don't move really slow or groan and moan. We ended up going with a very realistic style." He also noted that Inferi are skinnier than zombies, as well as being waterlogged and grey.
There is a scene in the movie, in which Death Eaters, led by Bellatrix Lestrange and Fenrir Greyback, attack The Burrow, where Harry, the Weasleys, Lupin, and Tonks are staying. This particular scene was not in the book, but was made just for the movie, to serve as a representative of all the news reports, which are scattered around in the source novel, about various attacks by Death Eaters on the wizard community. It was considered to provide better pacing for a movie to have Harry actually experience one such attack first hand, rather than hearing/reading about those that kept happening to some other students, or their relatives.
The omission in this movie, of the battle at Hogwarts between members of the Order of the Phoenix and Death Eaters, was due to the fact that the writers did not want to seek repetition, when they filmed the climactic battle of the final film.
The character Fenrir Greyback is a direct reference to Fenris the wolf as depicted in the Nordic mythology. In that myth, Fenris bit the arm of Tyr and was prophesied to be involved in Odin's death as will be killed by Tyr's brother Vidar during Ragnarok. The novel shares the similar mythology: Bill Weasley, Ron's brother was attacked, his face scarred during the skirmish with Fenrir like as Fenris bit Tyr's arm; like Fenris' involvement with Odin's death, Fenrir was among the group who was involved in Dumbledore's murder; Deathly Hallows resolves the story. An interesting fact that was never mentioned in the movie is that Fenrir was the wolf who infected Remus Lupin.
Arthur Bowen, the child actor that plays Albus Severus Potter (Harry's son) in the epilogue of the final movie, can be seen in this movie buying roasted chestnuts at a stand in Diagon Alley. At the time of writing, these two appearances are his only acting roles.