The making of a big-budget film is often fraught with issues. If it’s not a big star acting like a prima donna, it's expensive equipment malfunctioning, or directors struggling to maintain their artistic leanings in the midst of a gargantuan financial and logistical undertaking. Miraculously, The Dark Knight delivered on Christopher Nolan’s desire to turn the Batman story into a realistic, neo-noir film - without abandoning the thrill ride audiences were buying tickets for.
Behind the scenes, The Dark Knight was as tense as many of the film's most taut moments, from Nolan’s crew breaking one of the most expensive cameras on the planet to Heath Ledger losing sleep as a result of getting into character. The results - from the box office, to the Academy Awards, to its enduring reputation as one of the best superhero movies ever made - speak for themselves. But getting there certainly wasn't easy.
Heath Ledger's commitment to his role as the Joker is well-documented. He was so intense, in fact, that he didn't just treat Christian Bale as a scene partner but as a legitimate antagonist. The first scene the two filmed was the one-on-one interrogation, one of the key turning points of the movie - and the point at which Bale learned firsthand that Ledger wasn't messing around.
According to Bale, when the cameras were rolling, Ledger was genuinely needling him to get a rise out of the bat-suited actor. The whole thing escalated to Bale actually punching Ledger. Even without that blow, Ledger was intent on throwing his body into the role. Bale explained to The Hollywood Reporter:
[Ledger] was kinda egging me on. I was saying, "You know what, I really don’t need to actually hit you. It’s going to look just as good if I don’t." And he’s going, "Go on. Go on. Go on..." He was slamming himself around, and there were tiled walls inside of that set which were cracked and dented from him hurling himself into them. His commitment was total.
While conceiving plans for The Dark Knight, director Christopher Nolan wanted to find a way to make the Joker's makeup look like something from the real world, but with a surreal texture. One key inspiration was the work of Francis Bacon, which Nolan shared with Heath Ledger and makeup artist John Caglione.
The three were all influenced by the way the features of a figure in Bacon's paintings overlap one another, and they applied that principle to the actual paint on Joker's face, giving it a "worn through quality." Ledger's performance as the Joker also brings to mind the work of Bacon, specifically in the way the artist uses negative space. As the Joker, Ledger removes his backstory from the equation with a series of erroneous origins, forcing the audience to fill in that space for themselves.
It's well known that Ledger's turn as the Joker took an emotional toll on him - up to and including a severe lack of sleep. The role was so stressful on him that he almost stopped sleeping completely during production, getting only as much rest as he physically had to.
While speaking with the New York Times, Ledger said that while working on the film he "couldn't stop thinking," and that even though his body was exhausted his "mind was still going." In order to get a small amount of rest he resorted to taking sleeping pills.
"The pencil trick" is one of the film's most popular moments. The Joker jams a man's head onto a pencil that's stuck to the table, effectively making it disappear into the man's skull - a memorable punchline to his ostentatious self-introduction to Gotham's criminal kingpins. Rather than accomplish this via CGI or a collapsible pencil, the camera crew and editors just got crafty. One shot was done with the pencil, and the other was done without the pencil, a classic in-camera editing technique. The Dark Knight's production designer explained:
At the end of the day, you just shoot it twice: one with the pencil and one without the pencil. Then the edit does its magic. The previous film Chris [Nolan] and I did was The Prestige. We spent like a year on this Prestige thing learning magic tricks and how you do tricks of camera.