Early 35mm camera. This camera was developed in 1913 by Oskar Barnack, a German inventor. Barnack had originally invented a compact, lightweight movie camera which used film. He wanted to be able to test exposure times on short lengths of film before shooting a film, so he developed a camera with a frame size of 35x24mm and weighed 99.5% less than conventional photographic plate cameras. A production model was delayed until 1925 because of World War I. Manufactured by Leitz and called the Leica, 35mm cameras became immediate best sellers.