Étienne-Jules Marey (French: [maʁɛ]; 5 March 1830, Beaune, Côte-d'Or – 15 May 1904,Paris) was a French scientist, physiologist and chronophotographer.
His work was significant in the development of cardiology, physical instrumentation, aviation, cinematography and the science of laboratory photography. He is widely considered to be a pioneer of photography and an influential pioneer of the history of cinema. He was also a pioneer in establishing a variety of graphical techniques for the display and interpretation of quantitative data from physiological measurement.
Marey started by studying blood circulation in the human body. Then he shifted to analyzing heart beats, respiration, muscles (myography), and movement of the body. To aid his studies he developed many instruments for precise measurements. For example, in 1859, in collaboration with the physiologist Auguste Chauveau and the watch manufacturer Breguet, he developed a wearable Sphygmograph to measure the pulse. This sphygmograph was an improvement on an earlier and more cumbersome design by the German physiologist Karl von Vierordt. In 1869 Marey constructed a very delicate artificial insect to show how an insect flies and to demonstrate the figure-8 shape it produced during movement of its wings. Then he became fascinated by movements of air and started to study bigger flying animals, like birds. He adopted and further developed animated photography into a separate field of chronophotography in the 1880s. His revolutionary idea was to record several phases of movement on one photographic surface. In 1890 he published a substantial volume entitled Le Vol des Oiseaux (The Flight of Birds), richly illustrated with photographs, drawings, and diagrams. He also created stunningly precise sculptures of various flying birds.