a motion-picture camera that was used in the traditional animation process that moves a number of pieces of artwork past the camera at various speeds and at various distances from one another. This creates a sense of parallax or depth. wikipedia 
Sketch of a computer-controlled, 4-plane Multiplane camera sparetimelabs
The most famous multiplane camera was developed by William Garity for the Walt Disney Studios to be used in the production of Snow White and the Seven Dwarfs.
The camera was completed in early 1937 and tested in a Silly Symphony called The Old Mill, which won the 1937 Academy Award for Animated Short Film. wikipedia