Historically, in the United States motion picture cameras had been used since the 1920s for recording race-meets but were unsuitable for photo-finish photography as the frame rate was too infrequent to catch the critical instant horses or dogs reached the finish line. This record was achieved by using a special slit camera. Lorenzo Del Riccio, a Paramount Pictures motion picture engineer improved the circular flow camera, a device which had been invented in the 1930s especially for the purpose of photographing moving objects. The first racing club to make use of Del Riccio's 'Photo-Chart' camera for photo-finishes was the Del Mar Turf Club in California at its inaugural meeting in 1937.