The exhibition “Civic Radar,” a retrospective of the work of San Francisco artist Lynn Hershman Leeson, opened this week at Yerba Buena Center for the Arts. It is required viewing for anyone attentive to pioneers of feminism, the development of digital and performance art, or the cultural history of the Bay Area. It is, as well, a reminder that legends are part historical, part mythic — distilled narratives, best told free of muddling detail. Any good exhibition is an argument for a point of view with regard to quality, timeliness or significance. “Civic Radar” was organized by the German museum ZKM/Center for Art and Media and adapted here by YBCA Director of Visual Arts Lucía Sanromán. It makes a thorough case for Hershman Leeson’s political and media prescience.