From Caligari to Hitler: German Cinema in the Age of the Masses (2014).
All about the cinema of the Weimar Republic (1919-1933), featuring lots of restored footage of great old flicks. Fritz Lang, F.W. Murnau, Von Steinberg, many others I hadn't heard of. Doggone subtitled narration, which is a pain when you wanna see all that wild imagery. But good.
Sounds very interesting. So many great things came from the German impressionist film makers, post WWI. Not the least, the influence on horror and noir.