A polymorphic scientific, Etienne Jules Marey explored numerous techniques and disciplines, obsessed by one unique concept: movement. First interested in flight, he studied birds and imagined mechanical devices capable of flying. From 1878, he focused on movement within human beings and, inspired by Edward Muybridge he had met in 1881, used photography to document his research. He thus imagined, in 1882, a camera entitled photographic gun that enabled him to capture a moving subject in twelve poses. Etienne Jules Marey thus decomposed the gestures of men practicing sports, animals in motion, everyday tasks precisely observed and even the migration of air. He also invented the chonophotography that would be the precursor of cinema. Photography in its early days was the ultimate accomplice of reality but with Etienne Jules Marey (and Edward Muybridge), photography suddenly also captured the invisible.