Widescreen is independent of film width. Pathé Monoplex 4.75 mm film is an extreme example. 9.5 Pathé Duplex film (two perforations between each frame instead of one) went through the camera horizontally, with frames occupying half the width of the film. The film cartridge was flipped by the user when the end was reached and the opposite half of the film exposed. After developing, the film was split in half lengthwise (much like 8 and 16 mm film). The resulting frames had an aspect ratio of 1.6:1. The split film was called "Monoplex."

The format was introduced when Pathés 9.5 mm format was losing the competition with Kodak 8 mm. But the 4.75 mm system did nothing to rescue 9.5 mm. It was complicated and required a special camera and projector. The small frame meant a grainy image when projected at a typical size. The narrow film was easily damaged. It was discontinued within a year.