‘Photography at work in the sciences’ trains the debates about visualization on the very compelling medium of photography. The symposia pulls together scholarship from Science and Technology Studies, Anthropology, Art history, Photography and History of Science to analyze what happens to science when scientists produce, consume and disseminate photographic materials. Photography has often been presented as a benign, objective recording technique without agency that fits itself seamlessly to the purposes of sciences, and thus it has often been overlooked in more complex modeling of scientists’ behavior, and in the investigation of the concepts of observation and experiment. As a subject within scientific visualization, photography has also taken a smaller role than drawing, although from 1870 to 1960 it insinuated itself slowly into every aspect of modern science, from experiments and observations that are wholly dependent on a photographic method, through to the publication and exhibition of scientific results. Far from being merely an illustrative mechanism, photography plays an active role in forming scientific research questions, in defining scientific discovery and even in the very definition of some scientific disciplines. Yet we know very little about the role of photographers, photographic materials and industries in scientific practice, and there has been only sporadic concentration on the way in which visualizing with photography differs from visualizing with other media. The key questions of this symposia will be: how were photographs used to put knowledge to work; what are photographs’ boundaries?; and how do they help define discovery? We will interrogate these questions by looking at the transitional period of 1870-1960 with the aim of gaining a better understanding of the situated contexts of the use of photography in the sciences, as well as how this use changed over time. In ‘Photography at work in the sciences’, we will take stock of the current state of research, evaluate research methodologies developed in heretofore disparate fields, and generate research questions for this nascent, fast growing area of study.