Although Ricardo Cedeño Montaña does not frame his project as such, Portable Moving Images is perhaps the most ambitious contribution yet to the “format theory” and “general history of compression” proposed by Jonathan Sterne in his MP3: The Meaning of a Format. Portable Moving Images is an expansive but sometimes frustrating history of the successive “reductions” that transformed first film, then analog video, and finally digital video from complex technologies for professional media production to ubiquitous tools used by amateurs. In each process, Montaña argues, cameras and other equipment became not only smaller but also more automated; reduction in both mass and the complexity of operation facilitated widespread use of new formats. “Portable media,” he writes, “compress the media factory into takeaway apparatuses that are then poured into the streets.”