How many movies have Robert A. Dietrich and Theodor Loos collaborated on?

They have worked on 6 movies together! Their first movie together was The Artificial Man (1916) while their highest rated movie together was The Revenge of the Homunculus (1917). They have not worked together since Christian Wahnschaffe II: Escape from the Golden Dungeon (1921). They are most known for their horror films together.