Another SF-based giant of independent cinema will be honored this weekend with a three-day symposium about his work and influence. Belson (1926-2011) was a Chicago-born childhood SF emigre who studied painting in SF Art Institute, then UC Berkeley’s fine arts programs. So the “Cosmogenesis” event will be very special, as it features twenty or so titles including 16mm and digital preservations. There will also be lectures, spotlights on pioneering local multimedia and the Beat film scene (including a couple Maclaines), a “Listening Room,” and more. It opens Thu/25 at area theaters including SF’s Metreon, the Century Daly City, and Emeryville’s AMC Bay Street.