Film noir was never a single studio genre with a rulebook. The label was applied retrospectively to a body of American crime films sharing visual, thematic, and narrative tendencies: stark lighting, compromised protagonists, fatal choices, unstable identities, and a postwar sense that the system might be rigged.
Los Angeles was especially useful. The city offered modern offices and decaying mansions, bright sun and nighttime streets, anonymous apartment buildings and elite enclaves. A character could cross class boundaries in minutes and still feel trapped.
Double Indemnity turns insurance paperwork and suburban houses into engines of doom. Sunset Boulevard transforms a silent star’s mansion into a mausoleum. The Lady from Shanghai ends in a hall of mirrors where identity literally fragments.
The visual pleasure of noir is inseparable from its anxiety. Hollywood photographed its own city as a place where appearances were always evidence and never quite truth.