The essay aims to outline an epistemology of photography through the critical issues that arise from the encounter between photography and sculpture. In particular, it investigates the aesthetic and semiotic constraints that define the specificity of the photographic look with respect to a sculptural three-dimensional vision. The relationship between documentary and art photographs is the main area of research; specifically, the essay tries to highlight the interpretative value that can also be attributed to documentary photography, underlining the boundaries of a (...) complex distinction. A specific section is devoted to Medardo Rosso’s photographs of his own sculptures. Rosso’s work solicits a reflection on the status of photography and on some theoretical problems such as reproducibility, the relationship between original and copy, and the creative gap produced by variation in a series. The artist suggests a peculiar “grammar” of photography by virtue of his relationship with another art – sculpture. (shrink)