What is "Film Noir"?

Film noir literally means black film. It was discovered by French film critics who noticed how the trend of 'dark' and black was the theme of many American crime and detective films. Film noir usually refers to a distinct historical period of film history - the decade of film-making after World War II.

Characteristics and Conventions of Film Noir: Themes and Styles

• The primary mood of classic film noir were melancholy, alienation, bleakness, disillusionment, disenchantment, pessimism, ambiguity, moral corruption, evil, guilt, desperation and paranoia. 
• The most popular characters were as follows: Heroes (or anti-heroes), corrupt characters and villains included down-and-out, conflicted hard-boiled detectives or private eyes, cops, gangsters, government agents, a lone wolf, socio-paths or killers, crooks, war veterans, politicians, petty criminals and murdereres. 
• Film noir films were mostly shot in gloomy grays, blacks and whites which thematically showed the dark and inhumane side of human nature with cynicism and doomed love, and they emphasized the brutal, unhealthy, dark and sadistic sides of the human experience.  

• Film noir films were marked visually by expressionistic lighting, deep-focus or depth of field camera work, disorienting visual schemes, jarring editing or juxtaposition of elements, ominous shadows, skewed camera angles (usually vertical or diagonal rather than horizontal), circling cigarette smoke, existential sensibilities, and unbalanced or moody compositions.