Black-and-white film contains an emulsion that, when processed, changes colors into various shades of gray.
The earliest film stock was othochromatic–sensitive to blue and green light waves–and then panchromatic, which is sensitive to all light waves. By the end of the 1920s, panchromatic film stock, which creates an image and emphasizes contrasts and shadows, became the norm. The strong contrasts found in black-and-white film are apparent in this scene from Charles Laughton’s 1955 film, The Night of the Hunter.
By the late 1950s in Hollywood, with the development of Eastman Color, making films in color soon became the rule. However, there were still many films shot in black-and-white, ranging from international art films to independent U.S. productions. Today, to shoot in black-and-white is often an artistic or financial decision.