To many, the technological aspects of projection often go unnoticed, only brought to attention during moments of crisis or malfunction. For example, when a movie theater projector falters, the audience suddenly looks toward the back of the theater to see a sign of mechanical failure. The history of cinema similarly shows that the attention to projection has been most focused when the whole medium is hanging in suspension. During Hollywood's economic consolidation in the '30s, projection defined the ways that sync-sound technologies could be deployed within the medium. Most recently, the digitization of cinema repeated this process as technology was reworked to facilitate mobility. These examples show how projection continually speaks to the rearrangement of media technology. Projection therefore needs to be examined as a pivotal element in the future of visual media's technological transition. In Practices of Projection: Histories and Technologies, volume editors Gabriel Menotti and Virginia Crisp address the cultural and technological significance of projection. Throughout the volume, chapters reiterate that projection cannot, and must not, be reduced to its cinematic functions alone. Borrowing media theorist Siegfried Zielinksi's definition, Menotti and Crisp refer to projection as the "heterogeneous array of artefacts, technical systems, and particularly visual praxes of experimentation and of culture." From this, readers can understand the performative character of the moving image and the labor of the different actors involved in the utterance of the film text. Projection is not the same everywhere, nor equal all the time. Its systems are in permanent interaction with environmental circumstances, neighboring structures, local cultures, and social economies. Thus the idea of projection as a universal, fully autonomous operation cannot hold. Each occurrence of projection adds nuance to a wider understanding of film screening technologies.