The Corona satellites used special 70 mm film with a focal length camera. Manufactured by Eastman Kodak, the film was initially thick, with a resolution of 170 lines per mm (0.04 inch) of film. The contrast was 2-to-1. (By comparison, the best aerial photography film produced in World War II could produce just 50 lines per mm (1250 per inch) of film). The acetate-based film was later replaced with a polyester-based film stock that was more durable in Earth orbit. The amount of film carried by the satellites varied over time. Initially, each satellite carried of film for each camera, for a total of of film. But a reduction in the thickness of the film stock allowed more film to be carried. In the fifth generation, the amount of film carried was doubled to of film for each camera for a total of of film. This was accomplished by a reduction in film thickness and with additional film capsules. Most of the film shot was black and white. Infrared film was used on mission 1104, and color film on missions 1105 and 1008. Color film proved to have lower resolution, and so was never used again.