I saw this in Munich's legendary Werkstatt Kino -- where else? -- which presented a series of Alois Brummer films accompanying an exhibition about the "count of Porno" at the very beginning of his filmmaking career.
Brummer made softcore flicks -- neither pornographic nor really erotic but more t&a -- mostly because he quickly fathomed that it was a surefire way to make a lot of money out of otherwise cheap films with toe-curling titles such as, erm, "Count Porno And His Lovethirsty Daughters". He started out as the proprietor of a few cinemas, and quickly found out that the average "socially aware German movie" never turned a profit. So he made sexually titillating German movies.
The documentary follows Brummer around on his sets, and is -- by modern production standards -- almost primitive. This was clearly before non-linear editing, and the shoot-to-final ratio is at best 3:1. The interscene titles a typewritten sheets of paper, shot just for a few seconds to save on material. But because of this, it's practically as close to life as it gets. You couldn't fake the scene where a young farm wife throws a fit when she finds out that they're shooting a pervy movie in her cow barn.
