The essay analyses a 1934 photograph showing the making of a film in a workshop of the Renault Motor Company in Billancourt, France. What can this specific image tell us about photography, filming, and industrial work? It has limited historical value when viewed alone. One approach is to compare it to a corpus of related documents. Like any other historical vestige, images have to be interpreted in relation one to another as well as compared to other sources. They have to be (re)contextualized. A second approach is to investigate its archival origins. Returning as far as possible to the sources of an image, one can identify at least the logic of its conservation, and eventually the process of its making and the context of its usage. Thus, visual documents can become irreplaceable historical sources.