9.5 mm film
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Three frames of 9.5 mm film showing central sprocket holes |
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
shutter 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 that same frame 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.
* Film width: 9.5 mm
* Image size: 6.5 x 8.5 mm
* Image area: 55.25 mm
* vertical pulldown
* 1 central perforation per frame
* 49.4 frames per foot (7.4 mm per frame)
* 135.1 frames per metre
* 100 feet = approx. 5 minutes at 24 frame/s
* Soundtrack: magnetic, 1 mm wide
* Sound-Image frame interval: 28 frames
*
Film*
List of film formats*
Movie projector* Gauriat, Pierre (2001).
Le format 9,5 mm - Film size 9.5 mm. Retrieved Dec. 29, 2004.
*
Sub-35 mm movie film formats history webpage
