Since photography was invented, its techniques and uses have kept evolving throughout the 19th, 20th and 21st centuries. The Thirties marked a turning point when American anthropologists considered photographic images as a legitimate instrument for ethnographic research. Renewed historical conditions, migrations currents and the recent digital revolutions radically changed the connection between this media and the social sciences. Covering the three past decades, seven researchers on migrations and their visibility in global cities each contribute here to give an account of how photographic documentation moved from “social photography” to “participative photography” – nevertheless keeping ethnographic purposes in mind. Along this move, migrants may have become active participants in producing images, which enhance the city, more precisely their own neighbourhood, and in staging local otherness. As for the photographer-researcher, s/he may choose between a variety of positions, worki...