The surface of most heritage objects holds important clues about their creation. To answer specific research questions about the creation of a mural painting located in the Bishop’s Gate porch of St. Stephen’s Cathedral in Vienna, the three-dimensional geometry of the entire painted surface was digitised in minuscule detail using thousands of overlapping photographs. After a brief introduction to the basics of image-based surface digitisation, this paper describes in detail how the photographs were taken and how they were processed to create a digital three-dimensional surface. To appreciate the subtle surface variations encoded in this digital model, various relief visualisation techniques have been applied. The paper ends with a discussion of the new insights into the creation of this painting that are enabled by these visualisations.