Nikonos Underwater Camera System

Manufacturer: Nikon Type: Amphibious camera system (bodies, lenses, strobes) Years produced: 1963–2001 Mount: Nikonos bayonet (non-interchangeable with Nikon F)

Overview

The Nikonos was the only purpose-built underwater camera system for professional photographers for nearly four decades. Descended from the French Calypso camera designed by Jean de Wouters, the system was licensed by Nikon in 1963 and evolved through five main bodies (Nikonos I through V) plus the autofocus RS. Its dedicated UW-Nikkor lenses, designed to be optically corrected for water immersion without ports, remain unsurpassed in underwater optical quality even by modern housed-camera-behind-dome-port configurations. The system’s discontinuation in 2001 coincided almost exactly with the digital transition that Wetpixel was founded to document.

System History

Origins: Calypso to Nikonos (1963)

The system originated with the French Calypso camera, invented by Jean de Wouters. Nikon purchased the license in 1963 and began producing the Nikonos series. The original 35mm amphibian lens had approximately the same underwater field of view as a 50mm land lens, establishing Nikon’s naming convention where the nominal focal length must be multiplied by 1.33 (the refractive index of water) to obtain the true focal length. (^[1])

Nikonos I through V (1963–1984)

The system evolved through five generations:

• Nikonos I (1963): First production model based on the Calypso design
• Nikonos II (1968): Improved reliability
• Nikonos III (1975): Widely regarded as extremely reliable — “bullet proof for 3 decades” according to long-time users. Some remained in service 30+ years without internal O-ring service. (^[2])
• Nikonos IV-A (1980): Added auto-exposure but considered more flood-prone than other models, particularly through the back door seal. (^[3])
• Nikonos V (1984): Introduced TTL strobe control, which became the standard for underwater flash metering for the next two decades. As Alex Mustard wrote, “Ever since TTL strobe control was introduced with the Nikonos V in 1984 the vast majority of images have relied on it.” (^[4])

Flooding Reputation

Community opinions on Nikonos flooding varied by model. The III was widely considered extremely reliable. The IV-A was considered “the most flood-happy kludge ever made for underwater imaging.” The V was more maintenance-intensive, with floods most commonly occurring through the TTL pins in the sync socket or the shutter button O-ring — not user-serviceable areas. (^[5])

UW-Nikkor Lenses

The dedicated underwater lenses were the system’s greatest achievement. Because they were designed to operate immersed in water without a port (using water as the front optical element), they avoided the optical compromises inherent in all port-based systems.

UW-Nikkor 15mm f/2.8

The legendary wide-angle lens. Modern testing by Pawel Achtel using a RED Epic 5K camera demonstrated that the 15mm out-resolves even the highest resolution digital sensors available, achieving over 8K resolution — “something very few land lenses can achieve on land.” In comparison:

• A typical 9-inch dome port with an equivalent wide-angle land lens cannot resolve more than about 2K around the edges
• A flat port performs even worse, typically less than 1K resolution in equivalent setups
• The Nikonos 15mm achieves 1,434 line widths per picture height at 50% MTF at the edge of the frame, compared to 120 for a flat port and 140–351 for dome ports

The lens produces perfectly rectilinear (non-distorting) images underwater, is free from geometric distortion, and is sharp from corner to corner. (^[6])

Two versions exist: an earlier version (fits Nikonos I, II, and III only, as it blocks the TTL sensor of IV and V) and a later version compatible with all bodies. The earlier version reportedly performs slightly better due to its retrofocal design. (^[7], comments)

The 15mm could be knocked loose on land or in rinse buckets due to its large size, though water pressure at depth secured it firmly. Some photographers used duct tape for aggressive water entries with whales. (^[8])

Other UW-Nikkor Lenses

• UW-Nikkor 20mm f/2.8: Mid-wide option
• UW-Nikkor 28mm f/3.5: The first underwater-only Nikon lens; marked “28mm” though its underwater viewing angle was similar to a 35mm land lens
• UW-Nikkor 35mm f/2.5: Standard lens; the most commonly paired with the system
• W-Nikkor 80mm f/4.0: Telephoto option (water-resistant rather than submersible)

(^[9])

The Nikonos RS (1992–1996)

The RS (Reflex Submersible) was Nikon’s attempt at a professional underwater autofocus SLR. Essentially a Nikon F70 film camera in a compact waterproof housing, it featured a dedicated lens mount (same bayonet as Nikon F mount, but with a unique electronic protocol incompatible with standard Nikon cameras) and a suite of purpose-designed underwater lenses:

• R-UW AF 13mm f/2.8 Fisheye: The lens regarded as “the epitome of optical excellence in underwater wide-angle photography.” Its front element functions as a miniaturized dome port with varying glass thickness, producing superior results to any conventional dome setup. (^[10])
• R-UW AF 20-35mm f/2.8 Zoom: Versatile wide-angle zoom
• R-UW AF 28mm f/2.8: Prime wide-angle
• R-UW AF 50mm f/2.8 Macro: Close-focus specialist

The RS was astronomically expensive and had few buyers. A critical design flaw contributed to its early demise: Nikon used bright red silicone O-rings but failed to adequately warn users that silicone O-rings must never be used with silicone-containing grease, or they will swell. Many cameras flooded as a result. Nikon withdrew the RS from production in 1996 after only four years. (^[11])

Despite its commercial failure, photographers like Kurt Amsler who used the RS recognized its optical superiority. As Andrej Belic recounted from a 2002 workshop with Amsler: when asked whether he preferred his Subal-housed Nikon F5 or the Nikonos RS, Amsler pointed to the RS, saying “You don’t care about the optics and this is what it’s all about.” (^[12])

Discontinuation and the Digital Transition

Nikon discontinued the Nikonos V and its strobes (SB-104, SB-105) around 2001–2002, just as the digital revolution was transforming underwater photography. By 2005, new Nikonos V bodies were selling for around $250 on eBay, and Nikon was depleting its RS spare parts stock. (^[13])

The timing was significant. As Drew Wong noted, he “switched from Nikonos to video because of the limitation of 36 frames.” Digital’s instant feedback, unlimited exposures, and evolving image quality made the film-based Nikonos system increasingly difficult to justify — despite its optical superiority. (^[14])

Yet the transition was not without resistance. Experienced Nikonos users valued the system’s compactness, simplicity, and unmatched optics. As one forum member wrote in 2005: “What I like about the Nikonos are the optics, size and simplicity. You don’t have to worry about ports.” Others kept their Nikonos V with 15mm as backup wide-angle systems well into the digital era. (^[15])

Legacy in the Digital Era

Lens Adaptation Projects

The optical superiority of Nikonos lenses — particularly the RS series — inspired multiple projects to adapt them for digital use:

Andrej Belic’s Nikonos Conversion System (2012): Belic discovered that the RS lens bayonet is physically the same as Nikon F-mount, allowing RS lenses to fit on Nikon DSLRs. He developed electronic modifications enabling full autofocus, aperture control, and metering communication, plus waterproof adapters for Nauticam, Subal, and Seacam housings. Testing with the Nikon D800 at 60m depth proved the system’s corner sharpness far exceeded conventional dome port setups. (^[16]) (^[17])

Borut Furlan / Seacam conversion (2014): Slovenian photographer Borut Furlan took a different approach, splitting the RS 13mm into two components — the front element became a dome port, and the internal lens group became a modified lens for the camera. This avoided the adapter’s pressure and flooding risks and was commercialized by Seacam. (^[18])

Gates RS Adapter Kit (2014): Gates Underwater Products released a $5,625 adapter kit allowing all four RS lenses (13mm, 28mm, 50mm, 20-35mm) to work with their Deep Epic and Deep Dragon cinema housings, mapping focus and iris to housing controls. (^[19])

Achtel DeepX Housing (2012): Australian manufacturer Achtel built the first cinema housing designed specifically around Nikonos lenses (both RS and Nikonos V types) for RED Epic and Scarlet cameras, eliminating ports entirely. The UW-Nikkor 15mm, 28mm, 35mm, and 80mm could be used with quick lens changes. (^[20])

RS Lens Testing for Modern Sensors (2016)

John Ellerbrock of Gates tested RS lens image circles against RED’s 8K Vista Vision sensor (larger than full-frame 35mm). Results: the 13mm covered FF35 precisely with no margin; the 20-35mm covered 8K from 22mm onward; the 28mm and 50mm both covered the full 8K sensor. (^[21])

Continued Use in Underwater Cinematography

As of 2019, underwater videographers were still actively using the Nikonos 15mm lens on modern mirrorless cameras. Cave explorer Andy Pitkin filmed with a Sony A7S and Nikonos 15mm via Nauticam’s adapter plate, stating: “Tests have shown that the optical resolution of the Nikonos 15mm lens underwater is far higher than even a high-end surface lens behind even a big dome port.” The combination’s low-light capability (Sony A7S at up to ISO 25600) and optical quality (fixed f/8 for stunning depth of field) proved ideal for cave cinematography. (^[22])

Professional photographer Julian Cohen listed the “Nikonos 13mm Fisheye (Seacam conversion)” as his go-to wide-angle lens on a Nikon D4 in 2015. (^[23])

Nikon’s Continued Interest

In 2011, Nikon hinted at a modern Nikonos successor. Tetsuro Goto, Director of Laboratory R&D at Nikon Japan, said “Personally I think the Nikonos reborn in the future.” The resulting Coolpix AW100 (10m depth rating) disappointed enthusiasts. (^[24])

In 2013, Nikon released the 1 AW1 — the world’s first waterproof interchangeable-lens camera — rated to 15m with dedicated underwater lenses. While comparisons to Nikonos were inevitable, Adam Hanlon noted “it is important to note that the maximum depth of these is 15m, so it is still not a ‘proper’ underwater camera.” (^[25])

In 2018, Nikon re-registered the expired Nikonos trademark, sparking speculation about a possible digital Nikonos. The trademark had expired in 2008. No product has materialized. (^[26])

The Nikonos Project (2015)

Brandon Jennings created The Nikonos Project, a lending library of 80 Nikonos cameras available for free worldwide, celebrating the analog shooting experience. The project grew through donations from photographers who still had fondness for the system. (^[27])

The “Nikonos Connector” Standard

Even after the camera system’s demise, the Nikonos electrical sync connector became an industry standard for strobe connections. Housing manufacturers including Nauticam offered “Nikonos-style” bulkhead connectors as options for electrically-fired strobes, and strobe manufacturers like Inon and Ikelite continued to support the connector format. (^[28])

Community Discussion

The Nikonos system generated extensive discussion on Wetpixel forums throughout the 2000s–2010s:

• Film vs. digital quality: Early digital converts acknowledged that Nikonos slides could outperform digital, particularly in wide-angle corner sharpness, but accepted the trade-off for digital’s workflow advantages (^[29])
• Maintenance and flooding: Users shared practical knowledge about O-ring maintenance, lens mounting techniques, and the varying flood-proneness of different models (^[30])
• Adaptation attempts: The community followed RS lens conversion projects with great interest, with commenters expressing desire for adapters across multiple housing brands (^[31])
• Nostalgia and legacy: Many professionals who started careers on Nikonos maintained an emotional attachment. As Norbert Wu wrote, his first underwater photographs were taken with a Nikonos IV-A with extension tubes — “incredibly limiting” but producing images that “are probably better than the ones I take today with my fancy digital SLR housed systems” (^[32])

Timeline

• 1963: Nikon licenses the Calypso design and begins producing the Nikonos series
• 1975: Nikonos III released, becoming the most durable model in the line
• 1980: Nikonos IV-A adds auto-exposure
• 1984: Nikonos V introduces TTL strobe control, revolutionizing underwater flash photography
• 1992: Nikonos RS released — autofocus underwater SLR with dedicated lens suite
• 1996: Nikonos RS discontinued after only four years due to commercial failure and O-ring problems (^[33])
• ~2001–2002: Nikonos V and SB-104/SB-105 strobes discontinued (^[34])
• 2012-03: Achtel announces DeepX housing for RED cameras using Nikonos lenses (^[35])
• 2012-08: Andrej Belic publishes RS lens conversion project for Nikon DSLRs (^[36])
• 2012-10: Belic’s Nikonos Conversion System finalized for Nauticam, Seacam, and Subal (^[37])
• 2013-09: Nikon announces AW1 waterproof interchangeable-lens camera (15m depth) (^[38])
• 2014-05: Borut Furlan publishes Seacam RS 13mm conversion approach (^[39])
• 2014-11: Gates announces $5,625 RS Adapter Kit for cinema housings (^[40])
• 2014-12: Pawel Achtel publishes MTF tests proving UW-Nikkor 15mm superiority over dome/flat ports (^[41])
• 2015-06: The Nikonos Project launches lending library of 80 cameras (^[42])
• 2016-07: Gates tests RS lens compatibility with RED 8K Vista Vision sensor (^[43])
• 2018-08: Nikon re-registers expired Nikonos trademark (^[44])
• 2019-12: Andy Pitkin demonstrates Nikonos 15mm on Sony A7S for cave cinematography (^[45])

References