the late 1920s, Arnold was chosen to sit on a panel of industry experts in the fields of film engineering, projection, and cinematography to discuss and establish screen proportions and other issues which arose with sound pictures. The experts were chosen from four organizations: the Motion Pictures Arts and Sciences technicians, the Society of Motion Picture Engineers, the American Projection Society, and the American Society of Cinematographers. Through 1925 Arnold shot every film Viola Dana was in at Metro. This ended with Dana's departure from Metro in 1925 in order to go freelance. After her departure, Arnold was given a long-term contract by MGM, where he had been since they opened their west coast studios in 1916. That year Arnold filmed The Big Parade, which won the Photoplay Magazine Medal for best film of the year. The medal is considered the first significant annual movie award, prior to the establishment of the Oscars. 1927 saw the development of the "Arnold light", an incandescent light which replaced the arc lights which was used prior. In 1929 Arnold invented a new type of "sound-proof" camera, to reduce the noise in filming sound productions. Its first use was in Lionel Barrymore's The Unholy Night, although Arnold was not the cinematographer on that film. In 1929 Arnold invented the "bungalow", a mobile camera covering which freed cameramen from the restrictive camera booths which were necessitated by sound film photography. 1929 would be Arnold's last year behind the camera. In 1930 he joined MGM's administration as head of their sound camera department, later to be called simply the camera department. 1930s Arnold was elected to his first term as president of the American Society of Cinematographers in 1931, a position he would hold through 1937. He had previously been the treasurer of the organization. During the year he became a major force in campaigning for Cinematographers to receive on-screen credit. In 1932, American Cinematographer, the official magazine of the American Society of Cinematographers, decided to run a contest for the best amateur film, offering a $1000 prize. Arnold was selected to be one of the judges. Late in 1932 Arnold was elected to the Technical Committee of the Motion Picture Academy (MPA). Also in 1932, Arnold oversaw the creation of a standard testing practice by the ASC, whereby they would test all technical moving and still equipment. Equipment which passed the test were eligible to