This article charts the development of the modern astronomical observational system. I am interested most acutely in the digitization of this system in general, and in the introduction of adaptive optics in particular. I argue that these features have been critical in establishing the modern observatory as a factory for scientific data, rather than as a center of calculation in its own right. Throughout, the theoretical focus is on the nature of technological evolution in the observational system, understood as inextricably bound up with both the system-internal drive to surpass the limits imposed upon the distributed cognition of the researcher and the boundary at which empirical objects resolve themselves into technical objects. In short, this article explores the historically constituted character of expert astronomical perception, arguing that it is impossible to understand without constant reference to its material substrate.