What began life as the Calypso camera designed by famed diver Jacques Cousteau eventually became the Nikonos, Nikon's line of underwater, interchangeable lens viewfinder cameras. Over time, Nikon added automatic exposure and a variety of flash features and accessories to the Nikonos cameras.

The final model (Nikonos RS) was a fully-featured, autofocus, auto exposure SLR with a new, proprietary lens mount! These cameras are extremely rare.