The photo series The Sleepers by French conceptual artist Sophie Calle deals with the voyeuristic reciprocity of photographer and photographed subject and the (un)conscious renunciation of privacy. At Calle’s telephone request, 24 strangers agreed to sleep in the artist’s bed for eight hours while being photographed. Only people whose work forced them to sleep during the day were chosen. At the mercy of the camera, and despite their consent, it remained unclear to the photographed subjects what and when Calle photographed, when she only observed or even turned away. Calle took a photo every hour, documented in writing what the participants ate – depending on the time of day, they would be served breakfast, lunch, or dinner – and asked them questions that had nothing to do with factual knowledge, but served to establish a neutral and distant contact. Calles’ work resembles the experimental setup of a sleep laboratory; Calle, however, is not interested in the subjects’ sleeping behaviours, but in the power structures established through the act of photographing as well as testing personal boundaries.