Nauticam Water Contact Optics (WACP / WWL System)

Manufacturer: Nauticam
Type: water contact optics / wide-angle corrector ports and wet wide lenses
Designer: Edward Lai (Nauticam founder)
Year introduced: 2015 (WWL-1), 2017 (WACP-1)
Price range: $1,035 (WWL-C) to $3,283 (WACP-C)

Overview

Nauticam’s water contact optics are a family of purpose-designed underwater lenses that address the fundamental optical limitations of dome ports. Rather than relying on a curved air-water interface (dome port) to create a virtual image that a land-based lens then photographs, these optics use multi-element corrected glass designed specifically for the water-to-air transition. The result is dramatically improved corner sharpness, wider fields of view, and the ability to shoot at wider apertures compared to traditional dome ports — advantages that become increasingly significant as camera sensor resolutions exceed 40 megapixels (^[1]).

The system was designed by Edward Lai, Nauticam’s founder, who brought his background in precision injection molds and optics to bear on the problem. Multiple Wetpixel Live episodes feature Lai explaining his design philosophy and the process of developing water contact optics using computer-aided lens design software (^[2], ^[3], ^[4]).

The product family includes two categories: dry-mount corrector ports (WACP-1, WACP-2, WACP-C) that function as sealed port-and-lens combinations, and wet-mount conversion lenses (WWL-1, WWL-1B, WWL-C, MWL-1, EMWL) that can be attached and removed underwater.

Historical Context

The Dome Port Problem

The conceptual foundation for the WACP was laid well before its commercial release. In December 2014, Alex Mustard began experimenting with a custom optical corrector port for wide-angle underwater photography, posting test results on the Wetpixel forums. His prototype used an “underwater corrector” built by Carl Zeiss and custom-adapted for his housing by Pete Ladell. Mustard’s goal was to achieve improved corner sharpness with non-fisheye wide-angle lenses on full-frame SLRs (^[5]).

The core problem that water contact optics solve is the degradation introduced by dome ports. A dome port creates a virtual image underwater that the camera lens must then photograph. This introduces several optical compromises: corner blur (especially on full-frame cameras with rectilinear lenses), the need for small apertures (f/14 or higher) to achieve acceptable edge sharpness, and limits on minimum focus distance. As Mustard explained in his 2017 WACP review, the bottleneck to underwater image quality is “not the water itself, but the barrier between the air inside the housing and the water beyond” (^[6]).

Nikonos RS Legacy

The concept of water contact optics was not entirely new. Nikon’s Nikonos RS (1992) had water contact lenses designed specifically for the underwater environment. By 2015, companies like Seacam were converting original Nikonos RS 28mm lenses for use with modern Nikon SLR cameras, and these conversions rekindled interest in water contact optics as an alternative to dome ports (^[7], ^[8]). The WACP represented the first modern, purpose-designed system to take this approach.

Product Family

WWL-1 (Wet Wide Lens) — 2015

The WWL-1 was Nauticam’s first commercial water contact optic, introduced at DEMA 2015. Designed as an underwater lens taking into account water contact to minimize optical errors, it was described by Nauticam as a “breakthrough lens” at launch. It provided approximately 130 degrees field of view with compatible 28mm-equivalent lenses and supported full zoom-through capability, meaning photographers could go from wide scenic to fish portrait without removing the lens (^[9]).

The WWL-1 was a wet-mount design, attachable and removable underwater via Nauticam’s bayonet mounting system. It worked with compact cameras, Micro Four Thirds, APS-C mirrorless, and even full-frame mirrorless systems like the Sony a7R with the Sony 28mm lens, where it provided a semi-fisheye view and excellent close-focus wide-angle performance (^[10]).

WWL-1B — 2021

The WWL-1B was the next generation of the WWL-1, featuring the same optics but with an integrated aluminum buoyancy collar to make it nearly neutral in water. It shipped with a hard front cover and used the updated Bayonet Mount II system. Priced at $1,465, it maintained full zoom-through capability and was compatible with the same wide range of lenses and housings as the WWL-1 via Bayonet Converter II adapters (^[11]).

The WWL-1B was frequently paired with Sony’s compact FE 28-60mm f/4-5.6 lens, particularly on the Sony a7C, creating a compact travel-friendly wide-angle system (^[12]).

WWL-C (Wet Wide Lens Compact) — 2020

Announced at DEMA 2019 and shipping in July 2020, the WWL-C was designed specifically for compact cameras with 24mm-equivalent lenses, though it also worked with Micro Four Thirds and APS-C mirrorless systems. It was smaller and lighter than the WWL-1 (156mm diameter x 78mm, 1.05kg in air, 0.17kg in water) while maintaining 130-degree field of view and zoom-through capability. Priced at $1,035, it was the most affordable entry point to Nauticam’s water contact optics (^[13]).

Key specifications:

• 4-element lens construction with anti-reflective coatings on both sides
• Bayonet Mount II system (a new standard that replaced the original)
• 100m depth rating
• Compatible with Nauticam housings for Sony RX100 VII, Canon G5X Mark II, Panasonic LX100 II, Olympus TG-5/TG-6 (via adapter), and various M4/3 and APS-C cameras (^[14])

A key improvement over the WWL-1 for compact cameras was that the WWL-C worked at 24mm (the widest focal length of most compacts) without needing to zoom in to 28mm to avoid vignetting, making more of the camera’s zoom range available (^[15]).

WACP-1 (Wide Angle Corrector Port) — 2017

The WACP-1 was Nauticam’s flagship water contact optic, a dry-mount sealed lens-port combination designed for full-frame stills and high-end cinematography. It contained multiple elements of high-quality optical glass weighing approximately 3 kg (over 6 lbs), all designed to deliver excellent image quality underwater. With the flotation collar, it was 0.5 lbs negative in water (^[16]).

Key specifications:

• Maximum FOV: 130 degrees (at 28mm on full frame)
• Zoom range: 130 degrees to 57 degrees (with 28-70mm lens)
• Price: $3,250
• Weight: 7 lbs in air, 0.5 lbs negative with flotation collar
• Minimum focus: front element
• Mild barrel distortion (slight fisheye effect)

The WACP-1 was designed for use with lenses having a field of view up to 75 degrees (28mm on full frame, 14mm on M4/3). Nauticam initially favored Nikon 28mm primes (f/1.8 and f/2.8) in testing, while Mustard favored the Nikon 28-70mm f/3.5-4.5 for its versatility — a combination that produced a 130-degree to 57-degree zoom range, wider than the Canon 11-24mm (126 degrees to 84 degrees) and with superior edge sharpness (^[17]).

The WACP-1 was not restricted to any specific camera brand. Like Nauticam’s SMC macro converter, it could be used with any housing brand via appropriate adapters. However, physically smaller lenses tended to perform better than lenses with very large front elements (^[18]).

The WACP-1 provides approximately 4 f-stops of increased corner sharpness compared to traditional wide rectilinear lenses behind dome ports — meaning comparable corner sharpness at f/5.6 that would require f/16 or higher with a dome port (^[19]).

WACP-2 — 2019

Announced at DEMA 2019, the WACP-2 was designed to work with wider-angle lenses than the WACP-1, particularly the Nikon Z 14-30mm f/4. When combined with this lens, it offered a 140-degree field of view with sharpness across the whole frame, even at wide apertures. It featured a retractable shade (extended for dome protection, retracted to avoid vignetting), an N120 bayonet fitting, and the ability to focus in air, making split shots (over-under) possible (^[20]).

The WACP-2 was designed to be compatible with most lenses in the 16-35mm focal length range. The broader lens compatibility compared to the WACP-1 (which was optimized for 28mm lenses) caused some confusion in the community about which version to choose, prompting a dedicated Wetpixel Live episode explaining the differences (^[21]).

The WACP-2 used the larger N120 port system, making it compatible with Nauticam’s cinema and large-sensor housings. It was notably used with the Fujifilm GFX100 (102MP medium format camera) housing, where it provided excellent corner sharpness (^[22]).

Both WACP-1 and WACP-2 achieve ultra-wide 130-degree fields of view with reduced distortion, near-zero minimum focus distances, zoom-through capabilities, and superior corner sharpness at apertures as open as f/5.6 (^[23]).

WACP-C (Compact) — 2022

The WACP-C, announced in August 2022, was a lighter and more compact version of the WACP in the N100 port fitting. Like the WACP-1 and WACP-2, it was a dry-mount design functioning as both port and optical lens. It offered 130-degree field of view with lenses up to a full-frame equivalent of 28mm, with close focus to the front element and minimal distortion. Priced at $3,283 (^[24]).

The WACP-C provided approximately 3 f-stops of increased corner sharpness (compared to 4 f-stops for the WACP-1), representing a slight optical compromise for the benefit of reduced size and weight. Its zoom-through capability was demonstrated with the Sony 28-60mm f/4-5.6, which received a 69-degree to 130-degree field-of-view range (^[25]).

MWL-1 (Macro Wide Lens) — 2018

Previewed at Boot 2018 and shipping in October 2018, the MWL-1 was a different application of water contact optics: a wet-mount lens designed to convert a 60mm macro lens into a 150-degree ultra-wide-angle lens. This revolutionary concept allowed photographers to switch between macro and ultra-wide-angle on the same dive, even with full-frame DSLR systems. Priced at $1,850 (^[26], ^[27]).

Key specifications:

• FOV: 150 degrees with full-frame 60mm macro lens
• Lens construction: 7 elements in 5 groups (one aspherical element)
• Weight: 1.20 kg in air, 0.58 kg in water
• Dimensions: 108mm diameter x 120mm
• Focus: front element to infinity
• Depth rating: 100m
• Mount: Bayonet or M67 thread (^[28])

Jack Connick’s review for Wetpixel confirmed the MWL-1’s practical benefits: it could replace a large 9-inch dome port, 90mm extension, zoom gear, and camera lens, making travel significantly easier. He found best results at f/16 as recommended by Nauticam, with images softening below f/14 on the 46MP Nikon D850. The ability to use a double flip holder with an MWL-1 and an SMC diopter gave photographers fisheye to super-macro range on a single dive (^[29]).

EMWL (Extended Macro Wide Lens) — 2020

The EMWL was Nauticam’s most specialized water contact optic, designed for extreme Wide Angle Macro (WAM) imagery. Introduced in the second half of 2020, it was a modular system with interchangeable objective lenses at 60, 110, 130, and (from 2022) 160 degrees. The system allowed small subjects to be photographed at macro magnification within a wide-angle scene, creating the distinctive “bug-eye” perspective (^[30]).

The 160-degree objective lens, introduced in 2022, was the widest and featured a smaller front element that increased subject magnification while providing the widest background. Mustard’s field review in British Columbia found the sharpness “excellent” — “way, way in excess of any other ‘bug-eye’ style lens I have tried or seen” — though not quite matching the WACP or a prime macro lens. He noted the EMWL produced slightly warm images requiring processing below 4000K for neutral colors (^[31]).

Third-party adapters from Saga Dive expanded EMWL compatibility to non-Nauticam housings (^[32]).

Significance

The WACP represented a conceptual shift in underwater optics: instead of adapting land-based lenses for underwater use via dome ports, it introduced an optic purpose-designed for the water environment. As Nauticam’s Edward Lai explained in discussions with Wetpixel’s Adam Hanlon, the approach uses computer-aided lens design software to calculate corrections for the specific light dispersion properties of water, using different optical glasses and lens curvatures than would be needed for air-based optics (^[33], ^[34]).

The practical impact was substantial. A WACP replaces and outperforms a wide-angle lens, large dome port, and extension ring — making the $3,250 price more competitive than it first appears when compared to the total cost of the traditional system it replaces (^[35]). For video shooters, the ability to shoot sharp at wider apertures (gaining faster shutter speeds and lower ISOs) was particularly valuable.

The system also influenced how Nauticam designed housings. By 2020, new housing announcements routinely highlighted WACP and WWL compatibility. Housings for cameras like the Sony a1, Canon EOS R3, Canon 1DX Mark III, and Nikon Z9 were all described in terms of their compatibility with the WACP-1, WACP-2, and WWL systems (^[36], ^[37], ^[38], ^[39]).

Alex Mustard’s adoption of the WACP was particularly influential. His original 2017 review was widely read and became a key reference in discussions about optical quality. He continued using the WACP as his primary wide-angle system, pairing it with a Nikon D5 in a Subal housing, and later testing it with the Sony a7R V — the first full-frame mirrorless camera he preferred over his SLR underwater (^[40], ^[41]). He also used the WACP for photogrammetry work (^[42]).

Bayonet Mount System

Nauticam developed a dedicated bayonet mounting system for its water contact optics. The original system, introduced with the WWL-1 at DEMA 2015, featured large holes for venting air and attached to M67 threaded ports with a supplied tool (^[43]).

In 2020, Nauticam introduced the Bayonet Mount II system alongside the WWL-C. This was backwards-compatible in one direction: optics with the original bayonet mount worked with new Bayonet Mount II adapters, but newer optics like the WWL-C and WWL-1B were not compatible with original Bayonet Mount accessories. Bayonet Mount II became the standard moving forward, with a full range of holders, converters, and float arm adapters (^[44]).

Third-party manufacturers including Saga Dive produced adapters that expanded water contact optics compatibility to non-Nauticam housings (^[45]).

Community Discussion

Forum discussions about the WACP system were among the most active on Wetpixel’s Photography Gear and Technique forum. Common topics included:

• WACP-1 vs WACP-2 selection: The introduction of the WACP-2 at DEMA 2019 generated significant confusion about which version to choose, with the key distinction being lens compatibility — WACP-1 for 28mm-class lenses, WACP-2 for 14-35mm lenses (^[46]).

• Lens compatibility testing: Users actively tested combinations beyond Nauticam’s official port charts. The Canon RF 24-50mm f/4.5-6.3 was found to work well with the WACP-1 (N120 version) at its full 24-50mm range without vignetting, potentially offering 140-150 degrees at the wide end (^[47]).

• Sharpness troubleshooting: Some users reported sharpness issues that turned out to be caused by defective camera lenses rather than the WACP itself. Alex Mustard noted one case where a misaligned lens element caused blurry areas that moved with focus (^[48]).

• WWL-C vs WWL-1B selection: Users debated the trade-offs between the smaller, cheaper WWL-C and the optically superior WWL-1B for various sensor sizes and camera systems (^[49]).

• Buoyancy and rig balance: The weight of WACP and EMWL systems underwater was a recurring practical concern, with users sharing float arm configurations and buoyancy solutions (^[50], ^[51]).

Reviews & Discussion

• ^[52] — Alex Mustard’s comprehensive review covering optical theory, practical testing in Red Sea and Cuba, and image portfolio. Article (editorial source).
• ^[53] — Field review from Forgotten Islands expedition with Nikon D850. Article (editorial source).
• ^[54] — Review of newest EMWL objective, tested in British Columbia. Article (editorial source).
• ^[55] — Adam Hanlon and Alex Mustard explain the differences. Video episode.
• ^[56] — Edward Lai on the lens design process. Video episode.
• ^[57] — Edward Lai on how to get the best from the optics. Video episode.
• ^[58] — Edward Lai on history and philosophy. Video episode.
• ^[59] — Edward Lai on new products including WACP-C. Video episode.
• ^[60] — Mustard and Hanlon review wide-angle water contact options. Video episode.

Timeline

• 2014-12: Alex Mustard posts results of testing a custom optical corrector port (Carl Zeiss optic, adapted by Pete Ladell) on Wetpixel forums, demonstrating the potential of corrected water contact optics (^[61]).
• 2015-11: Nauticam introduces the WWL-1 Wet Wide Lens at DEMA 2015, their first commercial water contact optic (^[62]).
• 2017-06: Alex Mustard and Jason Isley begin field testing the WACP prototype in the Red Sea and Cuba (^[63]).
• 2017-09: Mustard publishes detailed WACP review on Wetpixel, explaining optical philosophy and sharing test results (^[64]).
• 2017-10: Production version of WACP shown at UK Dive Show 2017 by Nauticam UK/Underwater Visions (^[65]).
• 2017-11: WACP featured at DEMA 2017. Ships at $3,250 with flotation collar and carry case (^[66]).
• 2018-01: Edward Lai previews the M2F (later MWL-1) macro-to-wide conversion lens at Boot 2018, explaining his first work with achromatic water contact optics (^[67]).
• 2018-04: Full production WACP showcased at ADEX 2018. Drew Wong reports Lai’s explanation of using different optical glasses to counteract water’s light dispersion (^[68]).
• 2018-10: Nauticam ships MWL-1 at $1,850 (^[69]).
• 2019-02: Jack Connick publishes MWL-1 field review on Wetpixel, praising its travel-friendliness and versatility (^[70]).
• 2019-11: WACP-2 and WWL-C announced at DEMA 2019. WACP-2 offers 140-degree FOV with Nikon Z 14-30mm f/4, with split-shot capability (^[71]).
• 2020-07: WWL-C ships at $1,035 with Bayonet Mount II system (^[72]).
• 2020-08: Nauticam ships NA-GFX100 housing for Fujifilm GFX100, designed for WACP-2 compatibility (^[73]).
• 2020-H2: EMWL system introduced with 60, 110, and 130-degree objective lenses (^[74]).
• 2021-01: WWL-1B ships at $1,465 with integrated aluminum buoyancy collar (^[75]).
• 2022-08: WACP-C announced and ships at $3,283, a compact version in N100 port fitting (^[76]).
• 2022-09: EMWL 160-degree objective lens introduced; Mustard publishes field review (^[77]).

References

Wetpixel Live