Kodak Plus-X 5231

The 35mm motion picture stock was rated at ISO 80 in daylight and ISO 64 under tungsten lighting. This moderate speed made it well suited for well-lit scenes and outdoor shooting where fine grain was prioritized over low-light sensitivity.

Kodak Plus-X 5231 was introduced in 1956 and remained in production for several decades before being discontinued in the early 2010s. Its discontinuation came as part of Kodak's broader reduction of its film product lines during a period of financial restructuring and the industry's shift toward digital capture.

The 5231 designation refers to the 35mm format of the Plus-X motion picture negative film, while 7231 was the 16mm format equivalent. Both shared the same panchromatic black-and-white emulsion but were supplied on different film widths for different professional camera systems.

Kodak Plus-X 5231 was a panchromatic black-and-white motion picture negative film, meaning it produced a negative image that required further printing or processing to create a positive image. This distinguished it from reversal stocks, which produced a positive image directly after processing.