Trivia: Charles Foster Kane was based on publishing legend William Randolph Hearst and the movie has many in-jokes and gags given at Hearst's expense. The one that Hearst probably took the most offense to was the use of "Rosebud" in the film - it wasn't a childhood toy of his, but the pet name he had given his mistress' private parts.
Trivia: When the film was released, the Hearst newspapers refused to mention it by name, only calling it an "exciting RKO release." Before its release, publisher William Randolph Hearst, the owner of the newspapers, unsuccessfully attempted to block the film because he felt that the character of Charles Foster Kane is based on his life.
Trivia: This was the first motion picture to introduce "ceilings" into a shot of a scene taking place indoors from an actual set. Before this, due to the extreme lighting needed, the set was shot at angle that did not reveal that there was no ceiling on the set itself, otherwise it would have had to been shot indoors at a real location, which made for poor lighting that looked unrealistic. Orson Welles used a technique were a piece of thin cloth material was stretched over the top of the set which allowed the stage lighting to shine through, but appeared as a solid ceiling on film, further adding to the many other techniques used in this film to give the viewer a sense of realism.
Trivia: In the famous death scene, after the snow globe crashes, the snow does not remain in the globe (or on the floor,) but instead, takes over the entire screen. It was a mistake that was noticed by director Orson Welles, but kept for its dramatic effect; he felt that it added a sense of transcendence to Kane's death that was otherwise only implied.
Trivia: An interesting camera trick that Welles used during filming was that many of the shots of Kane were used with the camera looking up at him. For many of the "inferior" characters, the camera is always looking down on them - a subtle reminder of Kane's view of the world.
Trivia: To get most of his extremely low angle shots, Welles often had to dig a hole in the set to place the camera and its operator in, given the size of motion picture cameras at that time. The best example of this extreme low angle camera takes place after the political rally is finished.