Nikonos III

The Nikonos III underwater 35mm film camera was manufactured by Nikon from 1975 until 1980, and is the last model derived from the original French Calypso design inspired by Jacques-Yves Cousteau. Its purely mechanical design gives it a reputation for unmatched reliability.

Nikonos III added a bright-line viewfinder with parallax guides for close distance precision as well sprocket-gear frame spacing – not present on prior Nikonos models.

The standard lens is a Nikkor 35mm f/2.5 with zone focusing and a useful depth of field scale. On some Nikonos III samples the aperture knob is anodized black. Water's higher refractive index affects the behavior of optics: when submerged, the 35/2.5 yields a field of view equivalent to a ~47mm lens on land.

The protective planar glass front of the f/2.5 lens permits its use both above and below the surface, which is not true of some of the more specialized underwater-Nikkor lenses.