Although the photographic image has been part of the most contemporary art forms since the 1980s, the theoretical thinking that accompanied it is reaching a certain exhaustion and calls for a renewal of its fields of investigation. Following the exponential development of the digital universe and under the influence of cultural studies, research on the physiology of perception, action theory and the growing interest in theories of the spectator, new theoretical avenues are opening up for conceptual thinking about photography, not only as a technical object and process but above all about the photographic image as an object that acts and interacts. From 2013 the Labex Arts-H2H research project proposed a new approach to a "theory of photographic action", and in 2015 it opened the reflection, starting from photographic action, to the cross-fertilised research of different epistemological fields at a conference entitled "Quand l'image agit !", of which this volume gathers the proceedings and openings. Contributions by Stéphanie Airaud, Jean-Paul Avice, Alain Bernardini, Claire Bras, Michelle Debat, Jean-Paul Fourmentraux, Michel Guérin, Jacinto Lageira, Thierry Pozzo, Paul-Louis Roubert and Olga de Soto.