Random Trivia For This Title:
- Evanna Lynch beat 15000 girls and 29 finalists for the role of Luna. When it came to viewing the finalists, she was the ninth person in the audition videos and one of the producers, [?] David Barron stopped viewing after her saying, "She is Luna." Unknown to them, Lynch actually wrote a letter directly to J.K. Rowling.
- The Department of Mysteries set marks the first time that a totally computer-generated set was used throughout the movie. Building the set practically would have been too expensive since an estimation of 15000 crystal balls were needed and it would take a lot of time to clean and setup again were a retake required.
- According to the original script, the character of Kreacher was not intended to be in this film at all. But after J.K. Rowling read the script, she more or less insisted on him needing to be there to avoid some serious problems with future installments of the series. So, even if Kreacher still has no noticeable impact on the plot or story as it's presented in the film, a couple of scenes with him were added at the last minute based on this request.
- The radish earrings worn by Luna Lovegood were actually made by Evanna Lynch (the actress portraying her).
- Daniel Radcliffe came up with the idea that, as a gesture of respect to a teacher that Harry most certainly looked up to, he would wear a certain type of clothes that resemble the outfit worn by Prof. Lupin in his lessons from Harry Potter and the Prisoner of Azkaban, during his teachings. The director liked the suggestion, so that became the basis for his look during those scenes.
- In the scene where Harry, Ron, and Hermione are discussing Harry's kiss with Cho, the three begin to crack up near the end of the scene. This was all real laughter from the three actors. The director thought it was good for the scene and kept rolling.
- The set used for Igor Karkaroff's trial scene in Harry Potter and the Goblet of Fire was doubled in size for Harry's trial in this film, while still protecting its symmetry.
- Daniel Radcliffe can't tolerate contact lens, so in the scene where Harry is possessed, his eyes are digitally changed.
- Originally the death of Sirius Black appeared just as it does in the novel, with Bellatrix pushing him through the death archway after a longer one-on-one duel. Though filmed, the sequence was cut due to time and pacing issues. A portion of this original death scene remains in the final film: when hit with the killing curse, Sirius inexplicably floats backward though the arch.
- Harry's scream at the Department of Mysteries was cut out because it was too agonizing.
- Sirius Black's (Gary Oldman) death was foreshadowed and mentioned by Sybil Trelawney in the third novel Prisoner of Azkaban. J.K. Rowling's text line mentioned: "When thirteen dine together, the first to rise will be the first to die." In the dining room in Grimmauld Place, we see thirteen people including Sirius dining together and during a commotion with Mrs. Weasley, he got up first. When Sirius fell at the Department of Mysteries, this means that what Trelawney mentioned was accurate.