9.5 mm film is an amateur film format introduced by Pathé Frères in 1922 as part of the Pathé Baby amateur film system. It was conceived initially as an inexpensive format to provide copies of commercially-made films to home users, although a simple camera was released shortly afterwards.
It became very popular in Europe over the next few decades and is still used by a small number of enthusiasts today. Over 300,000 projectors were produced and sold mainly in France and England, and many commercial features were available in the format.
The format uses a single, central perforation (sprocket hole) between each pair of frames, as opposed to 8 mm film which has perforations along one edge, and most other film formats which have perforations on each side of the image. The single hole allowed more of the film to be used for the actual image and in fact the image area is almost the same size as 16 mm film. The perforation in the film is invisible to viewers as the intermittent shutter blanks off the light as the film is pulled through the gate to the next frame. In most 9.5 mm projectors, the also operated once whilst each frame was stationary in the gate to increase the apparent frame rate. In the later sound films, a 1 mm magnetic soundtrack was added, reducing the width of the image by 1 mm.
The width of 9.5 millimeters was chosen because 3 strips of film could be made from one strip of 35 mm film. This was useful when duplicating films because only 1 strip of 35 mm had to be processed. Then the sides, which contained the 35 mm sprocket holes, were cut off, the remaining film was cut into 3 strips, and the central sprocket holes added to each new strip.
The projection system also incorporated a way to save film on non-moving titles. A notch in the film was recognised by the projector which would then project the second frame after it for 10 seconds. By this method, 10 seconds of screen time was available for 1 frame of film, rather than the 160 frames required if the film was projected at the normal rate. (The same principle was used by the Agfa Family system of Super 8 camera and projector in 1981.)
In Britain, 9.5 mm film, projectors and cameras were distributed by Pathescope Ltd. During the years leading up to the Second World War, and for some years after the war, the gauge was used by enthusiasts who wanted to make home movies and to show commercially made films at home. Pathescope produced a large number of home versions of significant films, including Mickey Mouse and Betty Boop cartoons, classic features such as Alfred Hitchcock's Blackmail,and comedies by such well-known stars as Laurel and Hardy and Harold Lloyd. A notable element in the Pathescope catalogue were pre-war German mountain films by such directors as G.W.Pabst and Leni Riefenstahl.
Film for home cinematography was usually supplied in rolls 30 feet (9.1 m) long and enclosed in a "charger" or magazine. The most popular film was panchromatic black and white, but Kodachrome became available after some years, and Pathescope Colour Film (actually made by Ferrania) was introduced in the 1950s. A number of cameras and projectors were produced, the more successful including the Pathescope H camera and Gem projector. Films were also produced with an optical sound track for showing on projectors such as the Son.
After the war, the 9.5 mm gauge suffered strong competition from Kodak's 8 mm film, which was inroduced in 1936. Notwithstanding the far poorer resolution of the 8 mm frame, which could hold only about a quarter of the information of the 9.5 mm or 16 mm frame, 8 mm was taken up by a wider public, partly because of the commercial power of its sponsors. Pathescope found itself struggling to hold its place in the market. The company introduced the well made Prince 9.5 mm camera and Princess projector in the early 1960s, but the gauge was already doomed as a popular format. Despite a workers' buy-out in which the company name changed rapidly to Pathescope (Great Britain) Ltd. and then to Pathescope (London) Ltd., the firm was in receivership by the mid sixties. Nevertheless, the gauge has been kept alive by a dedicated group of enthusiasts who have used methods such as reperforating 16 mm film to provide continued supplies of material.
9.5 mm cine can suffer from uneven lighting on all but the best cameras. This is especially apparent as a lighter centre patch coincident with the sprocket holes and is due to the camera shutter not seating fast enough after exposure, usually due to poor quality construction or more often wear and tear.