Hans Richter (3m22s, c1923). Source: AVI, 30mb.
See also: vimeo.com/avantgardecinema/rhythmus21
"Erna Niemeyer-Soupault also claims that she photographed Rhythmus 21 and Rhythmus 23 in 1925 and 1926, and that these films were based on visual designs that Eggeling had laid out. Contradicting hers are two other asserions. First, Werner Graeff (who certainly doesn't hold Richter blameless in his treatment of collaborators) claims that he worked on Rhythmus 23 (which, when he met Richter, was called Fuge in Rot und Grun) and that it was completed in 1922. Second, Marion von Hofacker states (without giving the evidence) in her "Chronology" of Richter's career (in Foster, Hans Richter) that Film ist Rhythmus was shown at the final Dada soiree, Soiree du coeur de barbe. Against Graeff's claim is the fact that the publicity flyer for Novembergruppe's Filmmatinee, for May 3, 1925, lists only one film by Richter, Film ist Rhythmus. Given Richter's support for causes like those espoused by the Novembergruppe, it is hard to imagine that Rhythmus 23 would not have been shown it had been finished. And Hofacker's misidentification of Film ist Rhythmus as Rhythmus 23 - actually, the test strip that Richter showed under the title Film ist Rhythmus is only part of the middle of Rhythmus 23 - weighs against the authority of her assertions." (R. Bruce Elder, Harmony and Dissent: Film and Avant-Garde Art Movements in the Early Twentieth Century, p195)