Nikonos is the brand name of a series of 35mm format cameras specifically designed for underwater photography launched by Nikon in 1963.

At approximately the same time, Jean de Wouters was building the first prototypes of the Calypso for La Spirotechnique, which went into serial production in 1961.

[3] However, La Spirotechnique was not experienced with camera design and manufacture, so they approached Nippon Kogaku to license the production and sales rights in June 1961; the two companies signed a contract in February 1962 granting the worldwide sales and distribution rights to Nikon outside France and the European Economic Community.

Because of its waterproof housing, lens options, and toughness, the Nikonos was an important tool for photographers working in the steaming jungles, flooded rice paddies, and rain-lashed battlefields of the Vietnam War.

The viewfinder is used purely to compose the shot, and to display exposure information on bodies with internal metering (Nikonos IV-A and V).

[18] The three Calypso-based Nikonos models share the same basic structure where the complete camera consists of three modules: lens, housing, and shutter/film transport assemblies.

[14] A second viewfinder line was Nikon's complete re-design and included a through-the-lens (TTL) light meter with automatic exposure: In contrast to the prior Nikonos line, the Nikonos IV-A introduced a one-piece body using a hinged back for film loading; sealing was accomplished through numerous o-rings, including a large gasket for the back.

[9] The Nikonos V was capable of off-the-film-plane flash metering with the SB-102 speedlight, which was introduced alongside the camera at the Photo Marketing Association Show in Las Vegas, held April 1984.

Unlike its predecessors, the RS was a complete amphibious single lens reflex camera, with auto-focus, waterproof to 100 m (330 ft) and its own set of unique lenses that also utilized water-contact optics.

It is equipped with a high-eyepoint "action" finder, with an eye relief of 60 mm (2.4 in), allowing the user to wear a typical underwater mask.

[22] The RS represented the pinnacle of Nikon's commitment to underwater imaging, and generated significant interest at the time.

According to Brian Long, the RS was a development of Japan's bubble economy of the late 80s, which saw a number of cost-no-object consumer products and automobiles produced.

Non-Nikon (third party) silicone grease was commonly used without problems on black Nikonos o-rings by underwater photographers for several decades.

[28] The digital imaging portion was housed in an extended rear door and were largely identical to the options available for the contemporary Kodak DCS 420 cameras based on the Nikon F90.

[32][33] With the exception of the above-water only LW-Nikkor 28mm, all Nikonos Nikkor lenses use two knobs to facilitate focus and aperture operation with gloved hands.

Because the numbered Nikonos cameras did not offer through-the-lens viewing, the extremely shallow depth of field for macro photography pragmatically required a focusing aid.

The extension tube and Close Up Kit systems used a framer, which attached to the lens assembly and provided a direct physical index for the camera-to-subject distance, as well as its approximate width/height.

For various reasons (such as concern for potential damage to the reef), some alternative products were developed over time to minimize or replace the basic framer design.

One example (Fred Dion; Underwater Photo Tech) consisted of a bracket that held two small flashlights whose beams aligned at the focus plane.

[63] Because the SB-103 housing was designed to be pressure-resistant, Nikon was unable to crush the recalled units and instead drilled a hole through the "103" marking on the side of the flash.