Sonbert now moved to San Francisco, and his work in progress evolved into the hour-long "Carriage Trade" (1972), the film in which, as P. Adams Sitney has written, he "found the form that gave new meaning to his earlier work and defined his vocation." Intercutting footage shot with his 16mm Bolex during "travels over four continents in six years," "Carriage Trade" was the first in a two-decade succession of films with similarly radical montage, in which each cut was designed to open up multiple connections and associations. "From the first stunning cut, between building reflections in twin panes of glass and a distant waterfall that divides the frame similarly, the editing both expands the film's space and creates a variety of links between shots," wrote Fred Camper. "At times Sonbert tweaks the grandeur of his scenes (one magnificent image of Venice cuts to a pet puppy), but just as often he ennobles the ordinary (a man adjusting a woman's clothes becomes a flock of flamingos)."