Our concept of time and place has been changed by the work
of chronophotographers as it has done to those living in the era. Chronophotography is the name Étienne-Jules Marey (1882) uses to describe the time (chronos) photographs of movement sequences. For Marey his chronophotographs are a means to dissect, otherwise invisible stages of movement, for study. This is also true for the other chronophotographers although not always purely scientific. The chronophotographer has to know all the ins and outs of the photochemical process and the cameras he uses. He has to rely on his own knowledge or on that of instrument makers for the adaptations to the camera, the shutter and timing devices. Although Eadweard Muybridge starts as early as 1872 the technical limitations of the wet collodion plate and the conventional shutters makes it difficult to get good results. The wet collodion plate needs an exposure time of several seconds. This process is replaced by the dry plates (1880), the more sensitive gelatin bromide emulsion on paperfilm (1888) and finally the celluloid film (1890).