Fred Hill in 1969 did a camera test: He created an “in camera dissolve” on the Beaulieu. It was a tedious and difficult process.  Fred would first Iris down on the camera, then rewind the film, then shoot again on the same section of film while irising up to double expose the film. Fifty years later, it’s a relatively quick process on you Mac compared to how difficult this procedure was.

The Beaulieu R16 - motion picture camera first introduced in 1958.
Fred Hill – The Beaulieu R16 – Manual Dissolve In Camera Test

The Beaulieu R16 was a French based manufacturer of motion picture camera first introduced in 1958.  Marketed towards advanced amateurs, their goal was to offer high quality SLR style motion picture cameras.  The camera supports speeds from a single frame to 64 frames per second.  It is capable of using a 100 ft. film magazine internally.  The R16 can also be used to shoot sync sound, but it has a reputation for being a bit noisy.   The drive train offers a variety of standard special effects features: reverse drive for fades and dissolves, single frame filming for animation and time lapse photography and variable speed for slow and fast motion sequences.