René Tuma presents focused ethnographic case studies on video analyses in market research, sports training, and police work. Through careful reconstructions of the communicative activities of experts, the methods for interpreting video data are elaborated. The author illustrates these methods with meticulous reflexive videographic studies that highlight the relevance systems emerging as performative forms in showing, making visible, and interpreting. Based on this, he develops the concept of "vernacular video analysis," which refers to the dissemination of a specific way of seeing: video professionals align even the subtlest actions with the respective field logics and organizational issues, gradually establishing the analyses as a "service" for the respective professions in these fields.