Unlike other stylistic genres, film noir was not a genre that filmmakers of the classic Hollywood era set out to make. In fact, films in the so-called film noir style had been popular for six years before French film critic Nino Frank coined the term in 1946.
Frank used the term to describe lower-budget "dark film" crime dramas released by Hollywood studios. While the "gangster film" had existed since at least D.W. Griffith's 1912 short The Musketeers of Pig Alley, the specific style and presentation of film noir was new. Film noir emerged from the popularity of American hard-boiled crime fiction novels—low-cost, entertaining paperbacks popular in the 1930s. The popularity of these books, written by authors like Raymond Chandler, caught the attention of Hollywood. In fact, Chandler and other crime novelists found work writing film screenplays in the 1940s.
Because the category emerged after many film noir movies had been created, there is no universally agreed upon definition of film noir. However, there are some key elements that can be found in most examples of the genre.
The standard film noir protagonist is a private eye or detective, whose persona often has shades of grey, such as a dark past or moral ambiguity. Another standard character is the femme fatale: a desirable, aggressive woman with suspicious or uncertain loyalties. Film noir movies are often filled supporting characters who exist on the moral fringes of society, such as gangsters, gamblers, boxers, and nightclub performers.
Most film noir movies take place in New York City or Los Angeles. The city is presented as having both a glamorous surface and a seedy underbelly. Several film noir movies shot in Los Angeles took advantage of on-location shooting, rather than filming on a studio lot.
To cover for low budgets, film noir tends to feature stark lighting with heavy use of shadows. Shots of characters obscured by shadowing are common, particularly the technique of low-key lighting to create suspicious shadows.
Reflecting Cold War-era attitudes, many film noir films feature cynical or fatalistic tones, with protagonists put in desperate situations due to circumstances beyond their control. Other storytelling devices common to film noir are flashbacks and voiceovers in order to tell the story from a first-person perspective.
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