You will not find a better documentary about Detroit’s spectacular, world-historical decline than Detropia, a film by Heidi Ewing and Rachel Grady, the team behind the great and creepy Jesus Camp. What makes this doc better than the rest is, one, it’s simply beautiful, and, two, it’s mostly about how people (almost all of them black people, though we do encounter two white hipsters) are getting along, how they live day to day, how they love their dying city. This is a movie not about the ruins but the citizens of the ruins. (Northwest Film Forum, 1515 12th Ave,, 9 pm, $10, Oct 19–25)