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● A means of holding unexposed film, usually within the body of the camera, in such a way that
it does not become exposed to light; this generally means that the camera film is supplied in
short lengths due to space limitations.

● A means of holding the camera steady whist filming.
THE PROJECTOR
Whilst having some similar requirements to a camera, the projector has some important differences
and this is where the compromises come in -

Items one and two above are essentially the same in a projector – certain ‘niceties’ such as a
multiple pin claw and feed and take-up sprockets to assist with the handling of large size reels of
film are desirable.

● The shutter design needs to be quite different to that of a camera. The camera shutter is designed
for best light transmission and generally has a closed segment of about 40% of the pull down
cycle, with an open segment of about 60%. The shutter has one ‘open’ segment for each frame
of film transported through the gate. If such a shutter were used in a projector, a flicker rate
equal to the frames per second (FPS) that the film is running at would result; at a silent speed
of 16 FPS, this would result a severe flicker. For acceptable projection, the flicker rate should
be around 50 per second. At silent speed, this can only be achieved with a three-blade shutter,
a two-blade shutter is suitable at sound speed.
● A light source to illuminate the film for projection.

● A means of holding the film to be projected, possibly in lengths much greater than that originally
exposed in the camera, to allow the original camera films to be joined for a longer presentation.

Most of the camera projectors referred to later,
offered several compromises (and therefore
limitations) in some of the areas mentioned
above. Flicker was not such a big problem as
would be expected, as the illuminant was often
only a small touch globe, a very dim picture
resulted, limiting the image size to only a few
centimetres in width.

THE MIDAS 9.5 mm
This is probably the most widely found camera-
projector, first appearing in 1939. In Australia
they appear to have been mainly sold post war,
and in small quantities. To alleviate the need for
a tripod in camera operation, the film drive in
camera mode (only) was by battery-operated
electric motor. The battery pack being housed in
a clip on compartment attached to the side of the
camera. The unexposed film was housed in a
cassette attached to the rear of the camera; a
matching cassette mounted along side was used The Midas 9.5 mm Camera-Projector