Fincher used the Super 35 format to film Fight Club since it gave him maximum flexibility in composing shots. He hired Jeff Cronenweth as cinematographer; Cronenweth's father Jordan Cronenweth was the cinematographer who worked for Fincher on the 1992 film Alien 3 but left midway through its production due to Parkinson's disease. Fincher explored visual styles in his previous films Seven and The Game, and he and Cronenweth drew elements from these styles for Fight Club.
They applied a lurid style, choosing to make people "sort of shiny". The appearance of the narrator's scenes without Tyler Durden were bland and realistic. The scenes with Tyler were described by Fincher as "more hyper-real in a torn-down, deconstructed sense—a visual metaphor of what [the narrator is] heading into". The filmmakers used heavily desaturated colors in the costuming, makeup, and art direction. Helena Bonham Carter wore opalescent makeup to portray her romantic nihilistic character with a "smack-fiend patina". Fincher and Cronenweth drew influences from the 1973 film American Graffiti, which applied a mundane look to nighttime exteriors while simultaneously including a variety of colors.
The crew took advantage of both natural and practical light at filming locations. The director sought various approaches to the lighting setups, for example choosing several urban locations for the city lights' effects on the shots' backgrounds. He and the crew also embraced fluorescent lighting at other practical locations to maintain an element of reality and to light the prostheses depicting the characters' injuries. On the other hand, Fincher also ensured that scenes were not so strongly lit so the characters' eyes were less visible, citing cinematographer Gordon Willis's technique as the influence.
Fight Club was filmed mostly at night and Fincher purposely filmed the daytime shots in shadowed locations. The crew equipped the bar's basement with inexpensive work lamps to create a background glow. Fincher avoided stylish camerawork when filming early fight scenes in the basement and instead placed the camera in a fixed position. In later fight scenes, Fincher moved the camera from the viewpoint of a distant observer to that of the fighter.
The scenes with Tyler Durden were staged to conceal that the character was a mental projection of the nameless narrator. The character was not filmed in two shots with a group of people, nor was he shown in any over the shoulder shots in scenes where Tyler gives the narrator specific ideas to manipulate him. In scenes before the narrator meets Tyler, the filmmakers inserted Tyler's presence in single frames for subliminal effect. Tyler appears in the background and out of focus, like a "little devil on the shoulder". Fincher explained the subliminal frames: "Our hero is creating Tyler Durden in his own mind, so at this point he exists only on the periphery of the narrator's consciousness."
While Cronenweth generally rated and exposed the Kodak film stock normally on Fight Club, several other techniques were applied to change its appearance. Flashing was implemented on much of the exterior night photography, the contrast was stretched to be purposely ugly, the print was adjusted to be underexposed, Technicolor's ENR silver retention was used on a select number of prints to increase the density of the film's blacks, and high-contrast print stocks were chosen to create a "stepped-on" look on the print with a dirty patina.