How did cinematographer John Alton help create the visual style of Anthony Mann’s film noirs?

Cinematographer John Alton played a pivotal role in establishing the visual identity of Anthony Mann’s film noir projects during their six-film collaboration.1

Alton helped define the genre's aesthetic through his masterful use of deep shadows and stark, high-contrast lighting. This approach aligned with the broader tradition of film noir lighting, which drew inspiration from German Expressionism to emphasize the isolation and somber tone of the protagonists. By utilizing these dramatic lighting techniques, Alton and Mann created the visually indelible, moody atmosphere that became a hallmark of their work together, beginning with the 1947 film T-Men.12