Zen Underwater

Type: Dome port and optical accessories manufacturer
Founded: 2008 (first shown at LIDS, London, March 2008)
Headquarters: Fort Lauderdale, FL (3320 NE 32nd Street, Fort Lauderdale, FL 33308 — same address as Nauticam USA)
Founder: Ryan Canon (Reef Photo & Video / Nauticam USA)
Key products: DP-100, DP-170, DP-200, DP-230 optical glass dome ports; WA-100 wide-angle dome; FP-100 flat port; port adapters
Distribution: Worldwide through Nauticam USA (exclusive wholesale distributor in North America)
Contact: [email protected], [email protected]

Overview

Zen Underwater is a specialist manufacturer of high-quality optical glass dome ports and accessories for underwater photography housings. The company was founded by Ryan Canon, who was simultaneously the head of ^[1] in Fort Lauderdale and the principal of Nauticam USA. Zen’s core innovation was producing precision-ground Schott BK7 optical glass domes with broadband anti-reflective coatings, offered with interchangeable housing adapters that allowed a single dome to be mounted on housings from multiple manufacturers including Nauticam, ^[2], Sea & Sea, ^[3], Hugyfot, and Ikelite. (^[4])

Zen became particularly renowned for popularizing the mini dome concept in the late 2000s and early 2010s. Their DP-100 (4-inch/100mm) glass dome port helped ignite widespread interest in small dome ports for close focus wide-angle (CFWA) photography, a technique that had previously been confined to home-made accessories. Alex Mustard credited the introduction of the Zen 100 as the event that “reignited” the popularity of mini domes over the preceding five years, noting that “many photographers have experienced first hand the advantages of mini-domes” since its introduction. (^[5])

All Zen domes are ground from Schott BK7 optical glass and feature broadband anti-reflective coatings that reduce lens flare, ghosting, and internal reflections. The glass construction makes them extremely durable and resistant to scratching compared to acrylic alternatives. (^[6])

Founding and Origins

Zen Underwater Products was first shown publicly at the London International Dive Show (LIDS) in March 2008 by Ryan Canon, who was described as having “a major hand” in the new company. At the show, Canon demonstrated a dome port with an interchangeable adapter system that would allow mounting on a variety of housings — a key differentiator from housing manufacturers’ proprietary port systems. Alex Mustard reported from the show: “This dome is produced by a new company called Zen Underwater Products — that Ryan has a major hand in” and predicted that “they seem to have some exciting products (mainly ports) in the pipeline.” (^[7])

Ryan Canon was already a well-known figure in the underwater photography industry. He had been associated with Underwater Camera Pros (later Reef Photo & Video) since at least 2003, writing equipment reviews for Wetpixel. (^[8]) He went on to become the head of Nauticam USA when Nauticam entered the North American market in 2009, operating from the same Fort Lauderdale address that would serve as Zen Underwater’s headquarters. (^[9]) This close relationship between Zen and Nauticam USA meant that Zen products were distributed through Nauticam’s dealer network worldwide. (^[10])

Product Line

DP-100 (100mm / 4-inch mini dome)

The DP-100 is Zen’s signature product and arguably the dome port that popularized the mini dome concept for DSLR underwater photography. At approximately 100mm (4 inches) in diameter, it is a hemispherical optical glass dome designed primarily for fisheye lenses, offering significant advantages for close focus wide-angle photography. Its small size allows photographers to position strobes very close to the port for better lighting of extremely close subjects, and the reduced drag makes it ideal for freediving and high-current applications. (^[11])

The DP-100 was available in versions for Aquatica, Hugyfot, Ikelite, Nauticam, Sea & Sea (NX and RDX), and Subal (Gen. 3 and Gen. 4) housings, with an MSRP of $899 as of 2011. (^[12])

Compatible lenses included the Canon EF 8-15mm f/4L Fisheye, Canon 15mm Fisheye, Nikon 10.5mm Fisheye, Tokina 10-17mm Fisheye zoom, and Panasonic Lumix G Fisheye 8mm f/3.5. (^[13]) (^[14])

Alex Mustard described the DP-100 as optimal for crop sensor cameras with fisheye lenses, using it extensively with the Tokina 10-17mm on Nikon DX bodies. He considered 100mm to be the lower limit for 1.5x crop sensors with a 10mm fisheye. (^[15]) The Zen 100 was redesigned in early 2015 as a one-piece construction (replacing the earlier two-piece DP-100-S3 + PA-N85-S3 design) to improve compatibility with newer lenses like the Olympus 8mm f/1.8 PRO. (^[16])

DP-170 (170mm / ~6.7-inch dome)

The DP-170 is a mid-sized dome port positioned between the mini dome and the full-sized DP-230. It is constructed as a segment of a larger-radius dome (~110mm radius of curvature), making it more compact for travel while offering better corner sharpness than the DP-100 on larger sensors. (^[17])

The DP-170 was used by reviewers including Adam Hanlon for his comprehensive Nikon FX wide-angle lens test (with the Tokina 17mm f/3.5) and by Jack Connick for his D850 review (with the Sigma 15mm fisheye), who reported “excellent corners and quality.” (^[18]) (^[19])

Available in both N85 (Micro Four Thirds) and N120 (DSLR) mount versions. (^[20])

DP-200 (200mm / ~8-inch dome)

The DP-200 was a mid-range dome sharing the same radius of curvature as the DP-170 but with a taller profile, which positioned the center of curvature higher in the extension ring and reduced vignetting risk. It was primarily aimed at crop sensor users seeking better optical performance than the DP-170 without the bulk of the DP-230. (^[21])

The DP-200 was available for Aquatica housings at an MSRP of $1,399 as of 2011. (^[22]) It was eventually discontinued, likely due to market dynamics: Alex Mustard noted that the 200mm dome occupied a narrow niche between the more compact 170mm and the optically superior 230mm, and its primary audience — crop sensor shooters — represented a “shrinking part of the market” as photographers moved to full frame or Micro Four Thirds. (^[23])

DP-230 (230mm / ~9-inch dome)

The DP-230 is Zen’s flagship large dome port, offering the best optical performance for full-frame cameras with wide-angle lenses. Its large diameter creates a virtual image further from the lens with less curvature, making it easier to achieve sharp corners — particularly important with rectilinear lenses on full-frame sensors. (^[24])

The original DP-230 was available for Hugyfot, Nauticam, Sea & Sea, and Subal housings at an MSRP of $1,899 as of 2011. (^[25])

In 2015, the original DP-230-N120 for Nauticam was discontinued and replaced by the DP-230-N120-1124, which featured a larger inner diameter to accommodate the Canon EF 11-24mm f/4L lens. The new version shipped with a user-installable locking tab for backward compatibility with existing extension rings, and the price was reduced to $1,899 (down from $1,999 for the initial 11-24mm version). (^[26])

The Zen 230 was the go-to dome for many of the most prominent Wetpixel contributors. Adam Hanlon used it for all his Nikon FX wide-angle lens tests with the D810. (^[27]) Alex Mustard used it extensively with Subal housings for his Nikon D4, D5, and D850 work. (^[28]) (^[29]) (^[30]) Don Silcock used the Zen 230 with his Nikon D700, D800, and D500 setups. (^[31])

Micro Four Thirds Ports

Zen produced a dedicated line of ports for Olympus PT-EP series housings and Nauticam N85-mount Micro Four Thirds housings:

• WA-100-EP — Wide-angle dome for Olympus M.Zuiko 9-18mm and 14-42mm lenses on PT-EP01 housing ($499). (^[32]) (^[33])
• WA-100-EP714 — Wide-angle dome for Panasonic Lumix G Vario 7-14mm ($499). (^[34])
• DP-100-EP08 — 100mm glass dome for Panasonic 8mm Fisheye on PT-EP08 housing ($799). (^[35])
• FP-100-EP — Flat port for Panasonic Leica DG Macro-Elmarit 45mm ($399). (^[36])
• PA-EP08-EP — Port adapter allowing older PT-series Zen ports on the PT-EP08 housing ($100). (^[37])

Port Adapters

A key part of Zen’s business model was the interchangeable adapter system. When Olympus changed the port mount on its PT-EP08 housing (switching to a rotating bayonet latch), Zen responded by creating the PA-EP08-EP adapter to protect customers’ investment in existing Zen ports. (^[38]) Similar adapters existed for other housing systems, enabling a single glass dome element to be used across multiple brands.

The Mini Dome Revolution

Zen played a central role in what can be described as the mini dome revolution of 2009-2010. Prior to commercial mini domes, small dome ports had been “the reserve of the home-made accessory market” with “a small, but loyal following” — groups of friends sharing DIY designs, but not widespread adoption. (^[39])

By early 2010, Eric Cheng noted “quite a lot of activity in the forum discussing small dome ports,” with Zen and Seacam both offering ~100mm glass domes perfect for fisheye lenses. (^[40]) Alex Mustard compared this sudden availability to “London buses — you wait ages for one to turn up and then three come along at once,” as Aquatica, Seacam, and Zen all released commercial 100mm domes within months of each other. (^[41]) Aquatica’s competing Mini Dome 100 announcement specifically named “Zen Underwater and Seacam” as the companies it was joining in this market segment. (^[42])

The advantages of mini domes were significant for underwater photographers: smaller size and lighter weight for travel (important given increasingly strict airline baggage allowances), less buoyancy added to the housing, lower cost, and critically, the ability to position strobes very close to the lens for dramatically improved lighting in close focus wide-angle and wide-angle macro techniques. (^[43])

However, mini domes also had inherent optical compromises. Their small diameter creates a virtual image that is closer to the camera and more curved than with a standard dome, resulting in softer corners and requiring smaller apertures to maintain depth of field. Alex Mustard demonstrated these tradeoffs in his comprehensive 2010 article, noting that the compromises were more pronounced on full-frame cameras and with rectilinear lenses. He concluded that mini domes were best suited for dedicated close focus wide-angle work with fisheye lenses on crop sensor cameras, while larger domes remained superior for general wide-angle photography. (^[44])

Use in Major Wetpixel Reviews

Zen domes featured prominently in many of Wetpixel’s most important equipment reviews, reflecting their status as the de facto standard for optical glass dome ports:

• Canon 5D Mark II housing shootout (2010): Drew Wong used a Zen 8-inch glass dome (arranged by Ryan Canon/Reef Photo) with the Sea & Sea MDX-Pro housing. (^[45])
• Nikon D800 review (2012): Adam Hanlon used a Zen 230mm dome (supplied by Ryan Canon/Reef Photo) with the Nauticam NA-D800 for Wetpixel’s early-access review. (^[46])
• Canon EOS 6D + Zen DP-100 field review (2013): Adam Hanlon specifically reviewed the Zen DP-100 4-inch dome with a removable shade, paired with the Canon 8-15mm fisheye on the Nauticam NA-6D during the Wetpixel Ultimate Whale Shark expedition. (^[47])
• Subal ND4 review (2013): Alex Mustard used a Zen 230 dome with his Subal ND4 housing for the Nikon D4, including on the Kittiwake wreck in Grand Cayman. (^[48])
• Nauticam 140mm dome review (2014): Alex Mustard used the Zen 100 as a reference point, calling it the dome that “reignited” mini dome popularity, and photographed it alongside the Nauticam 140mm for comparison. He noted having a “Zen 170 on order too.” (^[49])
• Nikon D500 field review (2016): Adam Hanlon used a Zen 170mm dome with the Tokina 10-17mm throughout the review, shooting during the Wetpixel Raja Ampat Expedition and Lembeh Macro Workshop. (^[50])
• Nikon D500 Azores report (2016): Don Silcock used both Zen 100mm and 230mm domes with the D500, switching between them based on subject and conditions. (^[51])
• Nikon D5 UK shooting (2016): Alex Mustard used a Zen 230 dome with the Subal ND5 for his grey seal photography series. (^[52])
• Nikon FX wide-angle lens tests (2018): Adam Hanlon used the Zen 230mm dome for all lenses tested (14-24mm, 16-35mm, 20mm, 17-35mm) with the D810, and the Zen 170mm for the Tokina 17mm test. (^[53])
• Nikon D850 review (2018): Jack Connick used a Zen 170mm dome with the Sigma 15mm fisheye, reporting “excellent corners and quality.” (^[54])
• ONEUW 160x strobe review (2019): Alex Mustard used the Zen 230 dome with both his Subal ND5 and ND850 housings throughout the Red Sea test. (^[55])
• Nikon D500 mid-term report (2019): Don Silcock used a Zen 100mm dome with the Tokina 10-17mm and a Zen 230mm dome with the Tokina 11-20mm for his wide-angle work. (^[56])

Community Discussion

Zen products were extensively discussed in the Wetpixel forums, particularly in the Photography Gear and Technique section. Common topics included:

• Dome size selection: Choosing between the DP-100, DP-170, and DP-230 for different camera/lens combinations was a perennial discussion topic. Alex Mustard and Chris Ross provided detailed technical explanations of the optical tradeoffs between dome sizes, particularly the relationship between dome diameter, virtual image distance, and corner sharpness. (^[57])

• DP-200 discontinuation: Community members noted the DP-200’s absence from the product line. Alex Mustard speculated it was due to market forces rather than optical reasons — the dome occupied a niche between more popular sizes, and its primary audience (crop sensor users) was shrinking. (^[58])

• Zen vs. Nauticam domes: With Nauticam producing its own 140mm and 180mm dome ports, community members frequently compared them to Zen’s 100mm, 170mm, and 230mm offerings. Chris Ross noted that the Zen/Nauticam 170/180mm domes share similar optical characteristics (~110mm radius of curvature) and serve as compromises between optical quality and travel compactness. (^[59])

• Classifieds activity: Zen domes retained their value well on the secondhand market, with used DP-100 and DP-230 ports regularly appearing in the Wetpixel Classifieds section. (^[60]) (^[61])

Dome Port Theory

Zen’s products were central to many of the most important educational discussions about dome port optics on Wetpixel. Key principles discussed in relation to Zen domes:

• Virtual image: All dome ports create a curved virtual image close to the port. The camera must focus on this virtual image rather than the actual subject. Larger domes create a virtual image that is further away and less curved, making it easier to keep corners sharp. (^[62])

• Sensor size matters: Smaller sensor formats use shorter focal length lenses with inherently more depth of field, meaning mini domes work better with crop sensors and Micro Four Thirds than with full frame. Alex Mustard used an 80mm dome on 2x crop Olympus, 100mm (Zen) on 1.5x crop Nikon DX, and 150mm on full frame — representing what he considered the lower limits for each format. (^[63])

• Fisheye vs. rectilinear: Fisheye lenses are more forgiving behind smaller domes than rectilinear wide-angle lenses, which require larger domes for comparable corner sharpness. (^[64])

Product Timeline

• 2008-03: First shown at LIDS (London International Dive Show) by Ryan Canon, featuring dome ports with interchangeable housing adapters. (^[65])
• 2009-10: Ryan Canon establishes Nauticam USA at the same Fort Lauderdale address, creating the distribution partnership. (^[66])
• 2010-02: Eric Cheng highlights Zen and Seacam 100mm domes in Wetpixel editorial, noting significant forum discussion about small dome ports. (^[67])
• 2010-03: Alex Mustard publishes influential “Thoughts on Mini Domes” article using Zen 100 test shots, alongside competing Aquatica Mini Dome 100 announcement. (^[68]) (^[69])
• 2010-06: Zen 8-inch glass dome used in Drew Wong’s Canon 5D Mark II housing shootout. (^[70])
• 2010-07: Releases WA-100-EP dome port for Olympus Pen E-PL1 in PT-EP01 housing — early mirrorless dome solution with 100-degree wide-angle field of view using the 9-18mm lens. (^[71])
• 2011-09: Releases Canon EF 8-15mm f/4L Fisheye compatibility for DP-100, DP-200, and DP-230 domes. Updated DP-100 version with integrated extension available September 16, 2011. Published comprehensive compatibility charts for seven housing manufacturers. (^[72])
• 2012-05: Zen 230mm dome used in Wetpixel’s Nikon D800 review (supplied by Ryan Canon). (^[73])
• 2012-10: Announces DP-100-EP08 dome ($799) and PA-EP08-EP adapter ($100) for Olympus PT-EP08 housing (OM-D E-M5), addressing Olympus’s incompatible port mount change. Available October 15, 2012. (^[74])
• 2013-09: DP-100 featured in Adam Hanlon’s Canon EOS 6D + Nauticam NA-6D field review on the Wetpixel Ultimate Whale Shark expedition. (^[75])
• 2015-01: DP-100-N85 redesigned as one-piece construction, replacing earlier two-piece design. (^[76])
• 2015-06: Ships DP-230-N120-1124 dome for Canon EF 11-24mm f/4L lens ($1,999), featuring larger port opening. Available through Nauticam USA. (^[77])
• 2015-07: Releases compatibility for Olympus M.Zuiko ED 7-14mm f/2.8 PRO and 8mm f/1.8 Fisheye PRO lenses on both Nauticam N85 and Olympus PT-EP housings. (^[78])
• 2015-10: Discontinues original DP-230-N120, replaces with DP-230-N120-1124 at reduced $1,899 MSRP with backward-compatible locking tab. (^[79])
• DP-200 discontinued (date uncertain): Market dynamics led to discontinuation of the 200mm dome, as Alex Mustard and community members noted its narrow niche between more popular sizes. (^[80])

Key Relationships

• Nauticam: Nauticam USA served as the exclusive wholesale distributor of Zen products in North America, with both companies sharing the same Fort Lauderdale address under Ryan Canon’s leadership. (^[81])
• Reef Photo & Video: Ryan Canon’s retail operation, which supplied Zen and Nauticam products to reviewers and customers. (^[82])
• Alex Mustard: One of Zen’s most prominent users, shooting with the Zen 100, 170, and 230 across his Subal housings. His articles and forum posts provided extensive analysis of Zen dome optics. (^[83]) (^[84])
• Adam Hanlon: Used Zen domes for major Wetpixel editorial reviews. (^[85]) (^[86])

References