Reulos, Goudeau & Co. invent Mirographe, a 21 mm amateur format.
The Lumière Brothers premiere their new Lumiere Wide format for the 1900 World Fair. At 75 mm wide, it has held the record for over 100 years as the widest format yet developed.
Raoul Grimoin-Sanson also creates a sensation at the 1900 World Fair with his multi-projector Cinéorama spectacle, which uses ten 70 mm projectors to create a simulated 360-degree balloon ride over Paris. The exhibit is closed before it formally opens, however, due to legitimate health and safety concerns regarding the heat of the combined projectors and the highly flammable nitrate film.
W. C. Hughes redesigns the 17.5 mm format to have smaller perforations, and releases the format as La Petite.