Joao Moreira Salles’s spellbinding essay film assembles archival footage from Paris, Peking, Prague and Rio. Documentaries, anonymous footage, newsreels, home movies, photographs and radio broadcasts revisit youthful rebellion and society’s reaction in 1968. Salles, who narrates, bookends all this with footage his mother shot on her 1966 trip to Mao’s China. The fest’s most ambitious documentary is a mediation on cameras in times of political spectacle. Salles deconstructs with empathy the act of shooting. Smiles, tears and slogans draw his eye. Political martyrs and suicides in the era lend a tragic note. The wistful finale links a freeze frame of a smiling radical, the Lumiere Brothers’ 1896 film “Workers Leaving a Factory” and a song with the lyric “I’m too young to die.” 12:15 p.m. Oct. 20.

The Chicago International Film Festival continues through Oct. 26 at AMC River East 21, 322 E. Illinois.