The festival was the subject of a documentary movie titled "Monterey Pop" by noted documentary filmmaker D.A. Pennebaker. Pennebaker's team used recently developed portable 16mm crystal-sync motion picture cameras that stayed synchronized with double-system sound-recording systems. The film stock was Eastman Kodak's recently released "high-speed" 16mm Ektachrome 100 ASA color reversal motion picture stock, without which the nighttime shows would have been virtually impossible to shoot in color. Sound was captured by Wally Heider's mobile studio on a then state-of-the art eight-channel recorder, with one track used for the crystal-sync tone, to synchronize it with the film cameras. The Grateful Dead believed that the film was too commercial and refused permission for their performance to be shown. The screening of the film in theaters nationwide helped raise the festival to mythic status, rapidly swelled the ranks of festival-goers looking for the next festival, and inspired new entrepreneurs to stage more such festivals around the country. Adler said the cameramen were instructed to capture at least two complete songs for most of the acts, but for certain others, particularly the Who and Hendrix, to film as much of the sets as possible. As a result, only one song was not captured in part at least from both act's performances.