In this week’s issue Fred Camper weighs in on the 21st Onion City Experimental Film and Video Festival, which kicks off Tuesday, June 16, at the Gene Siskel Film Center and continues through Saturday, June 20, with programs at Chicago Filmmakers and Nightingale. Among the dozens of short films and videos screening are new works by Ken Jacobs, Ernie Gehr, Lewis Klahr, Jim Trainor, and Carolyn Faber.