Expressive, latterly balding German character actor who had his heyday in classic silent films under the direction of Fritz Lang. He was a watchmaker's son and, prior to deciding on an acting career, worked in an export business for musical instruments, as well as in an art dealership. He appeared on stage from 1912 and in his first film the following year. Perfectly suited to expressionist cinema, he excelled as King Gunther in the Nibelungen films "Siegfried" and "Kriemhild's Revenge", and as secretary Josaphat in _Metropolis (1927)_ . He acted in numerous classical plays on the stage, giving 400 performances in "Peer Gynt" alone. From 1949 until his death, Loos belonged to the ensemble of the Staatstheater Stuttgart.
