The self-contained amphibious underwater Calypso 35mm film camera was conceived by the marine explorer Jacques Cousteau (1910–1997), designed by Jean de Wouters and manufactured by Atoms in France.

The portion of the internal mechanism that protrudes above the outer shell contains the built-in optical viewfinder for the 35mm standard lens, the shutter speed selector and rewind knobs, the winding mechanism and shutter release, and an accessory shoe for separate viewfinders to suit various purposes.

At the base of the camera, a special flash sync connector is protected by an aluminium plug that can be removed by a coin and is sealed by an o-ring.

A small rewind knob at the left-hand top is extended for easy access and to engage the film transport mechanism.

No rewind release facility is required; this function was later added to the Nikonos and marked R on the shutter-speed dial.

[5] Inside the camera, the film cassette engages the rewind fork at the top, and it is held in place by a hinged retaining ring at the bottom.

The film lead passes under the fixed black film-pressure plate on its way to the slotted large diameter take-up spool.

[9] The vertical running metal-plate focal-plane shutter of the original Calypso has speeds from 1/30 to 1/1000 second, but a year later that was changed to 1/15 to 1/500 second.