Inon D-2000

Manufacturer: Inon
Type: Strobe
Year introduced: 2004
Successor: Inon D-200 (September 2018)
Guide number: 20 (ISO 100, air, 1 meter) / GN 65 in feet
Beam angle: 100 degrees circular
Depth rating: 100 meters
Power: 4 x AA batteries
Modes: S-TTL, External Auto, 13-step Manual, Nikonos TTL
Color temperature: 5,500K (native)
Flash duration: Approximately 5x shorter than conventional underwater strobes (Z-220, YS-90)
Underwater weight: 47g (negative)
Price at launch: $509 USD

Overview

The Inon D-2000 was a landmark underwater strobe that replaced the popular Inon D-180 and became one of the most discussed and influential pieces of underwater photography equipment of its era. Announced at DEMA 2004 in Houston, Texas, where Mark Rupert of Inon America demonstrated it to the Wetpixel crew, it went on sale November 8, 2004 at a price of $509 (^[1], ^[2]). The strobe was specifically targeted at underwater consumer camera photographers using Canon, Olympus, or Nikon OEM housings who wanted automatic flash exposure control without requiring an electrical sync cord connection (^[3]).

The D-2000 was notable for being an optically-triggered-only strobe at launch — there was no sync cord connection, which was a deliberate design choice to serve the compact digital camera market. It was later joined by the D-2000W and D-2000Wn variants (announced October 2005) that added 5-pin Nikonos-type bulkhead connectors for DSLR use (^[4]). The strobe went through multiple revisions, with the “Type4” being the final production version that remained in Inon’s lineup until being superseded by the D-200 in September 2018 (^[5], ^[6]).

S-TTL Technology

The D-2000’s most notable — and most debated — feature was its S-TTL (Slave TTL) mode. This system used optical detection of the camera’s built-in pre-flash to automatically set strobe exposure, achieving TTL-like automation with digital cameras without requiring electrical connections (^[7]).

How S-TTL Worked

According to Inon’s official technical explanation published on Wetpixel, the D-2000’s flash tube was engineered to have a flash duration and waveform closely matching those of typical compact camera built-in flashes (such as the Canon S-60 and Olympus C-5060). Inon provided oscilloscope waveform comparisons showing this match. This allowed the D-2000 to “exactly duplicate” the camera’s controlling signal — when the camera’s TTL metering system quenched its internal flash, the D-2000 would stop firing at the same time, producing equivalent exposure (^[8]).

This was fundamentally different from competitor solutions like the Heinrichs Digital Adapter 2 (DA2), which used an external adapter to relay slave TTL signals to conventional strobes like the Inon Z-220. Inon claimed that existing strobes like the Z-220 and Sea & Sea YS-90DX had flash durations approximately five times longer than the D-2000, making them inherently less accurate for slave TTL operation because their slow discharge curves caused exposure variation at different shooting distances (^[9]).

The D-2000 also employed a fiber optics system that prevented the strobe’s own flash light from affecting its sensor — the slave sensor was “designed to obscure from light” and the Inon Optical Cable Holder fixed the fiber optic to face directly at the internal strobe via a mirror-coated plate. This made it immune to the optical feedback problems that plagued conventional slave TTL systems, especially in macro photography where strobe reflections could overwhelm the sensor. The D-2000 used “real-time” TTL rather than “recorded” TTL — meaning there was no restriction on shutter speed (recorded TTL systems typically required shutter speeds no faster than 1/250) (^[10]).

The S-TTL Controversy

The S-TTL system generated extensive debate in the Wetpixel community. Julian Scheunemann (“Jolly”) published comparative testing of the D-2000’s S-TTL against the Heinrichs DA2 + Z-220 combination in late 2004, finding that the DA2 setup produced more consistent exposure across a range of apertures. He also noted that the D-2000’s focus light was not suppressed during the pre-flash sequence, which affected TTL metering accuracy (^[11]). Early forum reactions were pointed: “Consistency of the TTL exposure of the Matthias’ DA2 is superb” wrote user “reyer,” while “richorn” concluded “It appears to me that Matthias has beaten Inon in this test” (^[12]).

Mark Rupert of Inon America responded directly on Wetpixel forums, attributing the inconsistent test results to improper fiber optic cable positioning and failure to use the red focus light filter seal. He outlined three necessary conditions for proper S-TTL operation:

1. Correct fiber optic cable positioning using Inon’s dedicated fixture with mirror-coated plate to ensure the camera’s internal flash signal reached the D-2000 at full strength
2. Application of the red focus light filter seal when using the focus light, because the focus light remained on during pre-flash (contributing extra light the camera metered) but turned off during main flash, creating an exposure discrepancy
3. Use of Inon’s Clear Photo Film to completely block the camera’s internal flash visible light while allowing infrared wavelengths to pass for triggering

Rupert noted: “We appreciate people with time and interest testing our strobes but unfortunately sometimes the test parameters are wrong, leading to inaccurate test results” (^[13]).

Inon Japan published an official response to the community debate on Wetpixel, providing oscilloscope waveform comparisons and detailed technical explanations. They acknowledged that Scheunemann’s tests “seem to lack accuracy” due to testing methodology. Regarding the focus light issue, they explained it was a deliberate design: the focus light illuminated subjects brighter for autofocus, and the camera calculated exposure factoring in this light. When the focus light turned off during the main flash, the resulting exposure was reduced by the focus light’s contribution — “This is normal characteristic and feature of a camera.” The red filter and diffuser panel red filter were provided as countermeasures (^[14]).

EV Compensation System

The D-2000 featured a rear-mounted EV Controller dial for adjusting flash exposure compensation underwater. In S-TTL Low mode, users had 5 steps of negative compensation and 3 steps of positive compensation from the “B” (base) position. If exposure was still insufficient after maximum positive compensation in S-TTL Low mode, users could switch to “S-TTL” mode for more powerful output (^[15]).

The dial markings were notoriously confusing — early users struggled to understand the “Auto,” “B,” “+A,” and “-C” designations without an English manual. User “raintonr” discovered through trial and error that “if you leave the right hand knob on ‘Auto’ while in S-TTL mode things are over-exposed” and that the dial should point to “B” for base exposure (^[16]). Adam Hanlon later described the markings as having been “legendary in their difficulty in figuring out what they mean,” noting with wry humor that users could turn their strobes “not just to level 10, but to 11, perhaps a little brighter than everything else” — a Spinal Tap reference. In 2013, Inon released replacement E.V. dial labels with a clearer graduated scale showing half-power increments from -0.5 to -6, using luminous material for low-light visibility. The D-2000’s guide numbers at each setting ranged from GN 17 at full power (-0.5 EV) down to GN 2.5 at minimum power (-6 EV) (^[17]).

Technical Advantages

Fast Flash Duration

The D-2000’s flash duration was approximately five times shorter than conventional underwater strobes like the Z-220 and YS-90 series. Community member Herb Ko noted from Inon’s waveform data that the full exposure output of the D-2000 could be captured at shutter speeds as fast as 1/1000 second, whereas a Z-220 would deliver only about one-quarter of its output at that speed. He observed: “Looks like TTL stuff aside, this is a great strobe for the D70 and all the consumer digitcam like the Olympus 5050 that has a fast syncing electronic shutter. This allows sync speeds up to 1/1000 without the loss of strobe exposure” (^[18]).

Alex Mustard confirmed this advantage in his UwP Magazine review, noting that “the flash duration is much shorter than other similarly powerful underwater strobes” and that “this is helpful to the digital underwater photographer because it allows us to shoot fast shutter speeds with digital compact cameras without losing flash power” (^[19]).

Julian Scheunemann (“Jolly”) offered a counterpoint, suggesting it might be “easier picking up a more powerful strobe and obtaining the same effective guide number (with less than full power setting) within the D2000’s short flash duration,” noting that at half power, flash duration could be 1/4 to 1/5 of full-power duration (^[20]). Herb Ko disagreed, noting that more powerful strobes were invariably bigger and heavier, and that having flash exposure independent of shutter speed eliminated a variable from the shooting process (^[21]).

Clear Photo System

The D-2000 was compatible with Inon’s Clear Photo System, which used a special film placed over the camera’s built-in flash that blocked visible light while allowing infrared wavelengths to pass. This served dual purposes: it prevented the camera’s internal flash from contributing to the exposure (avoiding backscatter and fill from on-axis light), while still allowing the optical triggering signal to reach the D-2000’s fiber optic cable. Mark Rupert listed additional benefits: preventing the internal flash from filling shadows created by the external strobe’s angle, and eliminating the internal flash as “a major source of backscatter, and lens flare & ghosting” (^[22], ^[23]).

Accessories and System Integration

Mounting and Optical Cables

Inon developed an extensive ecosystem of camera-specific mounting bases and optical cable kits for the D-2000. Each compact camera housing required a dedicated “D Base” or “AD Mount Base” for attachment, along with a specific “Optical D Cable/Cap” set for fiber optic connection. Examples included kits for the Olympus PT-020 housing (for the C-5060), the Olympus PT-026 housing (for the Stylus 500), and the Canon WP-DC40 housing (for the S70/S60) (^[24], ^[25], ^[26]).

Diffusers

The D-2000 accepted snap-on diffusers in multiple variants:

• -0.5 Stop White Diffuser — standard light reduction with neutral color, widening beam to circular 110 degrees
• -0.5 Stop Blue Diffuser — designed specifically for Canon cameras whose JPEG engines tended to produce warm or “pinkish” exposures with strobe light. Mark Rupert of Inon America noted this color shift at DEMA 2004 (^[27])
• Color Temperature Conversion Filters (4900K and 4600K) — released June 2012, these reduced the strobe’s native 5,500K color temperature to produce richer blues in wide-angle images. Available in both standard and -0.5 diffused versions. Compatible with D-2000, D-2000S, D-2000W, D-2000Wn, Z-220 series, and Z-240, though External Auto mode was not usable with filters attached. Announced by Alex Mustard in the first Wetpixel Hangout (^[28]). Community members noted cheaper alternatives: user “Rich” cut Lee Conversion Filter Gel #206 for $7.00 per sheet, enough for 20+ strobes (^[29])

Use with DSLR Housings

Although originally designed for compact cameras, the D-2000 found use with DSLR systems through several pathways:

• Inon Optical Converter — a small strobe that plugged into a Nikonos V socket and connected via optical cable to the D-2000, enabling use with housed DSLRs. Alex Mustard noted that this converter was “quite expensive.” The converter only understood Nikonos TTL protocol, so S-TTL would not work properly with Canon E-TTL cameras via this route (^[30], ^[31])
• Nexus fiber optic sync ports — Nexus offered fiber optic sync ports for their Nikon D80, D200, and Canon 5D housings that could fire the D-2000 using the camera’s pop-up flash through a fiber optic cable (^[32])
• Inon X-2 housing — Inon’s own housing for Canon 10D/20D/30D DSLRs featured optical sync bulkheads allowing S-TTL compatibility with the D-2000 (^[33], ^[34])
• Olympus PT-E03 — the Olympus E-410 DSLR housing supported TTL operation with the D-2000 via fiber optics and the camera’s pop-up flash (^[35])

For DSLR users choosing between the D-2000 and Z-220, James Wiseman recommended the Z-220 for DSLR use due to its sync cord capability, noting the total cost of two D-2000s plus optical converters equaled or exceeded two Z-220s (^[36]).

English Manual Controversy

A notable early issue was the lack of an English instruction manual. Inon initially shipped the D-2000 with Japanese-only documentation, and with the release of the D-2000, Inon decided not to publish the English manual online, requiring users to contact their vendor. This created frustration among early adopters who could not find English instructions. User “anthp” posted on Wetpixel in February 2005 seeking help, and user “reyer” confirmed the policy, linking to a “big discussion” on digitaldiver.net about the issue. Buyer “raintonr” from Australia reported mail-ordering from California Digital Diving because no Australian dealers stocked the D-2000, and had to request a manual separately. Japanese vendor Yuzo Kanda produced his own English translation in PDF format for customers (^[37]).

Variants

D-2000s

A variant shown alongside the original D-2000 at DEMA 2007 as part of Inon’s full strobe lineup, with details differing only slightly from the base model (^[38]). The D-2000s was still being sold used on Wetpixel classifieds as late as 2022, with “Type 2” units going for around $250 with ULCS ball mount adaptors (^[39]).

D-2000W and D-2000Wn

Announced in October 2005 as replacements for the Z-220F, these variants added a 5-pin Nikonos-type bulkhead connector to the D-2000 platform. The “Wn” variant supported Nikonos-type electrical signals for wired TTL with Nikonos cameras, while both models retained optical S-TTL for compact digital cameras. Power output remained identical to the original D-2000 at GN 20. Julian Scheunemann speculated the new models continued to “offer TTL for digicams via optical connection and wired operation for DSLR cameras (no TTL) or Nikonos type cameras.” The addition of the sync cord connector addressed one of the original D-2000’s most significant limitations — the inability to use sync cords for DSLR and Nikonos systems (^[40]).

D-2000 Type4

The final production revision, the “Type4” designation was used for units still being sold as late as 2017 alongside the Z-240 and S-2000 in Inon’s strobe lineup. It maintained S-TTL compatibility with modern camera systems including the Olympus E-M1 Mark II in the PT-EP14 housing, where S-TTL Auto required the camera’s flash mode to be set to “Fill-in flash” and connection via Inon’s Optical D Cable Type L/Double Hole Rubber Bush Set (^[41]).

Community Reception and the TTL Debate

The D-2000 arrived at a pivotal moment in the TTL debate within the underwater photography community. While the strobe’s S-TTL innovation was technically impressive, a growing contingent of experienced photographers was moving away from TTL entirely.

Alex Mustard wrote an influential 2006 editorial titled “The Trouble with TTL” in which he was photographed shooting with a D-2000 while simultaneously arguing that most digital photographers “rapidly realise that not only is manual strobe control ridiculously easy with the instant feedback of the camera’s LCD screen, but it also empowers them with more creative control.” He characterized the demand for TTL as a hangover from film photography habits: “each photographer who converts from film to digital cannot believe that they do not need TTL. TTL is such an essential part of film shooting. Each photographer has to go through the learning process for himself. They cannot be told.” Mustard confessed to being “part of the problem” — he had housed a Nikon SB80DX speedlight for TTL with his D100 before becoming “one of the most vehement critics of the necessity of TTL” (^[42]).

The article sparked 19 comments with vigorous debate. James Wiseman, who had reviewed the D-2000 for Wetpixel, noted that TTL was valuable for his wife Sarah’s mainly-macro shooting with the Ikelite eTTL2 system in Bali, as “it allowed Sarah to concentrate on composition and finding subject, not having to change strobe power herself.” User “bvanant” argued that for fast-moving subjects like lionfish, there was “a single chance to get the shot you want” and TTL provided crucial insurance. User “scorpio_fish” called the piece a summary of “the echo chamber of Wetpixelian thought on TTL” and challenged the implication that “real photographers don’t need or want TTL.” Photographer “ehanauer” sided with Mustard: “The best light meter is the LCD display on the back of your camera” and “I was a reluctant convert to TTL toward the end of my film shooting days, but never missed it when switching to digi.” Professional photographer Mauricio Handler countered that manual control was essential to “the creation of images that transcend time” (^[43]).

The D-2000 was also reviewed positively in UwP Magazine issue 23 (March 2005) by Alex Mustard, who called it “an innovative and important product for digital compact photographers” (^[44], ^[45]).

James Wiseman’s Wetpixel Review

James Wiseman conducted the primary Wetpixel review of the D-2000, testing it with an Olympus C-5060 in a PT-020 housing. He approached the test as “any normal photographer that had just purchased new equipment from a dealer” — opening everything, assembling, reading instructions, and shooting. His methodology matched his earlier Ikelite Canon eTTL2 test: a series of exposures at different f-stops with the strobe deciding power output. He tested both manual power control and S-TTL modes, initially making the error of leaving the EV dial on “Auto” rather than “B” position, which still produced “decent results” — testament to the strobe’s robustness (^[46], ^[47]).

Reviews & Discussion

• ^[48] — Announcement and specifications by Herb Ko
• ^[49] — Comparative test by Julian Scheunemann
• ^[50] — Wetpixel review by James Wiseman with S-TTL and manual testing
• ^[51] — Inon Japan’s official technical response with oscilloscope waveform data
• ^[52] — Comprehensive review with Olympus C-5060 and Canon S400 testing
• ^[53] — Alex Mustard editorial on TTL vs. manual, featuring D-2000 use
• ^[54] — Adam Hanlon review of replacement dial labels for D-2000 and Z-240

Community Discussion

• ^[55] (12 replies) — Early comparative testing sparked response from Mark Rupert of Inon America defending proper test methodology. Users “richorn” and “reyer” initially sided with the DA2 results
• ^[56] (11 replies) — User asking which Inon strobe to pair with a Canon DSLR; James Wiseman recommended Z-220 for DSLR use, noting cost parity when adding optical converters
• ^[57] (16 replies) — Users struggling to find English manual; Inon initially shipped with Japanese manual only. “Reyer” provided detailed EV dial operating instructions
• ^[58] (5 replies) — Discussion of James Wiseman’s review, with Alex Mustard noting his positive UwP review
• ^[59] (6 replies) — Herb Ko highlights the strobe’s fast flash duration advantage for high-speed sync; Scheunemann offers counterpoint about larger strobes at reduced power
• ^[60] (7 replies) — Discussion of D-2000W and D-2000Wn variants with sync cord connectors; Scheunemann questions differences between W and Wn models

Timeline

• 2004-10: Inon D-2000 announced at DEMA 2004 in Houston, priced at $509; Mark Rupert of Inon America demonstrated the strobe to Wetpixel crew (^[61])
• 2004-11: Sales begin November 8; detailed specifications published — GN 20, S-TTL/External Auto/13-step Manual/Nikonos TTL modes, 100-degree circular beam (^[62])
• 2004-11: Julian Scheunemann publishes early D-2000 vs. DA2+Z220 comparative test showing DA2 with more consistent exposure (^[63])
• 2004-12: Mark Rupert responds on Wetpixel forums with three-point methodology correction, attributing test inconsistencies to improper fiber optic positioning and missing red filter (^[64])
• 2005-02: Julian Scheunemann publishes detailed S-TTL technology comparison on Wetpixel (^[65])
• 2005-02: James Wiseman publishes Wetpixel review, finding S-TTL “works as advertised”; initial tests used incorrect EV dial setting but still produced decent results (^[66], ^[67])
• 2005-02: Users report difficulty obtaining English instruction manual; Inon decided not to publish English manual online, requiring vendor contact (^[68])
• 2005-03: Alex Mustard publishes positive in-depth review in UwP Magazine issue 23, calling it “an innovative and important product for digital compact photographers” (^[69], ^[70])
• 2005-03: Inon Japan publishes official S-TTL explanation on Wetpixel with oscilloscope waveform data, responding to community debate (^[71])
• 2005-03: Herb Ko highlights D-2000’s fast flash duration advantage — full output at 1/1000s shutter speed vs. 1/4 output from Z-220 (^[72])
• 2005-05: Inon releases D-2000 mounting accessories for Olympus PT-026 and Canon WP-DC40 housings (^[73], ^[74])
• 2005-10: D-2000W and D-2000Wn variants announced with 5-pin Nikonos bulkhead connectors, replacing Z-220F (^[75])
• 2006-01: Alex Mustard publishes “The Trouble with TTL” editorial, photographed shooting with a D-2000; sparks 19-comment debate (^[76])
• 2006-09: Nexus announces fiber optic sync ports for D80/D200/5D housings compatible with D-2000 (^[77])
• 2006-11: D-2000 shown alongside Z-240 at DEMA 2006; Inon X-2 housing for Canon DSLRs features optical S-TTL compatibility (^[78], ^[79])
• 2007-07: Olympus PT-E03 housing for E-410 DSLR confirmed compatible with D-2000 via fiber optics for TTL (^[80])
• 2007-10: D-2000 and D-2000s shown at DEMA 2007 as part of Inon’s full strobe lineup (^[81])
• 2008-10: Inon S-2000 announced at DEMA 2008 with GN 20 and 100x more sensitive optical sensor; Alex Mustard comments that he wishes they had chosen a different name as “it is easy to get it confused with the INON D-2000” (^[82])
• 2012-06: Color temperature conversion filters (4900K and 4600K) released for Z-240/D-2000 series, announced by Alex Mustard in the first Wetpixel Hangout (^[83])
• 2013-06: Inon releases replacement E.V. dial labels for D-2000 and Z-240 with clearer graduated scale and luminous markings; Adam Hanlon admits he will miss “turning my strobes up to 11” (^[84])
• 2017-07: D-2000 Type4 confirmed compatible with Olympus E-M1 Mark II / PT-EP14 for S-TTL Auto via Optical D Cable (^[85])
• 2018-09: Inon D-200 announced as successor, shipping September 8. Improvements over D-2000: dome lens delivering 110-degree underwater coverage without diffuser, T-shape twin flash tubes, improved heat dissipation via metal heatsink, 220-lumen focus light with fresnel lens, enlarged control dials for thick gloves, phosphorescent back panel, and dramatically reduced underwater weight (4g vs. D-2000’s 47g). Like the D-2000, the D-200 remained optical-trigger only (^[86])

Legacy

The D-2000 was produced for approximately 14 years (2004—2018), an exceptionally long production run for underwater photography equipment. Its S-TTL system influenced subsequent Inon strobes including the S-2000 (2008), Z-240, and eventually the D-200 and Z-330, all of which retained the S-TTL concept. The strobe’s fast flash duration — an engineering side-effect of matching compact camera flash characteristics — proved to be one of its most enduring practical advantages, allowing full-power output at high shutter speeds long before this was a common feature.

The extensive community debate it sparked about S-TTL accuracy and the broader question of TTL vs. manual flash control became a defining conversation of the mid-2000s digital transition in underwater photography. The D-2000’s successor, the D-200, addressed many of its shortcomings — confusing dials, heavy underwater weight, and heat management — while retaining the core S-TTL technology and optical-only triggering philosophy.