The Duchatellier camera is essentially a film magazine to fit on the standard French deMaria camera bodies, of the 18X24 centimeter size. In its simplest form it embodies a shutter (the regular focal-plane shutter of the camera being removed) and a film-moving mechanism, both actuated by a single motion of the hand. Automatic and semi-automatic operation are accomplished by an auxiliary mechanism to which Bowden wires from the hand lever are attached. The motive power is an air propeller. Variation of speed is obtained by changing the point of contact of a roller on a friction disc, the disc being directly connected to the propeller shaft, the roller to the camera drive shaft.
The most distinctive features of the Duchatellier camera is its use of the focal-plane shutter to hold the film flat during the exposure. As already explained, this is accomplished by pressure, velvet strips on the shutter edges keeping the film close against the back plate. The return of the shutter curtain opening. A fixed-aperture variable-tension shutter is used. The magazine carries a roll of film long enough for 200 exposures, feeding the long way of the picture. When film needs to be changed in the air, this is done by changing the entire magazine, including its shutter curtain to the "set" position is accomplished by locking it to the film by perforating points, so that it is pulled across as the film is wound. This introduces between each pair of pictures a strip of tremendous over exposure, as wide as the: