Paper: Sad frenzy, fearful anger: Mask function, emotional contrasts and un/photographability of Japanese Noh theatre using the example of the visual layers of the Hannya mask; Potentially transferable concepts and questions for an expanded mask philosophy. Conference: The fourth workshop in the series ›Archäologische Grundbegriffe‹ is dedicated to the concept of mask. In analogy to the successful workshop on mosaic, the focus is on an idea that will serve as a key to the question of the aesthetic and ethical dimension of ancient images and objects. The archaeological concept ›mask‹ refers to specific object genres: theatre masks, ancestral masks, mask images, mask models. The mask opens up our view of concepts, rituals and processes associated with these objects. Secondly, the concept of the mask refers to a fundamental anthropological and technological phenomenon. It refers to that curious group of odd entities that interpose themselves between subject and object, between human and human, and between human and machine: images and screens, masks and surfaces, faces and interfaces, curtains and windows. We are particularly interested in the dual nature of such instances. Masks conceal, disguise, obscure — and at the same time they mediate, translate, explain. The workshop is part of the project ›Pre-Modern Elements of a Digital Image Theory‹, funded by the DFG Priority Programme 2172 ›The Digital Image‹. Organisation: Andreas Grüner, Julian Schreyer.