Inon Z-240

Manufacturer: Inon
Type: Strobe
Year introduced: 2006 (announced March)
Discontinued: Early 2017
Successor: Inon Z-330
Predecessor: Inon Z-220
Guide number: GN 24 (in air, ISO 100); GN 16 with diffuser (measured by Alex Mustard in 2017)
Beam angle: 100 degrees circular (without diffuser); 110 degrees with -0.5 diffuser
Color temperature: 5,500K native; 4,900K or 4,600K with optional color conversion filters
Weight: 670g (722g for the Retra Flash, by comparison)
Power: ~20% more powerful than the Z-220
Batteries: 4x AA NiMH (2,700mAh recommended); 320 full-power flashes per charge
Flash modes: S-TTL auto, 13-step manual (half-stop increments), 24-step external auto, Nikonos TTL
Sync: Optical slave sensor + Nikonos-type 5-pin electrical connector
Built-in features: LED aiming/focus light (not aligned with flash axis)
Production variants: Type 3, Type 4 (core design unchanged throughout)

Overview

The Inon Z-240 was arguably the most widely used compact strobe in underwater photography during its 11-year production run (2006-2017). Announced in March 2006 by Eric Cheng as Inon’s new flagship strobe, it succeeded the Z-220 with approximately 20% more power (GN 24 vs. the Z-220’s lower output), S-TTL auto exposure, 13-step manual power control in half-stop increments, 24-step external auto, and legacy Nikonos TTL for film camera compatibility. Its compact body, universal AA battery format, and 320 full-power dumps per charge made it the benchmark against which virtually every new strobe was compared for over a decade ([1]).

The Z-240 was displayed publicly at DEMA 2006 alongside Inon’s D-2000 strobe and the new X-2 SLR housing ([2]). By DEMA 2007, it was already established as one of Inon’s “popular strobe models” alongside the D-2000, D-2000s, and Z-22 ring strobe ([3]).

Alex Mustard’s standardized 2017 strobe comparison — the most rigorous comparative test published on Wetpixel — measured the Z-240 at GN 16 with diffuser, equivalent to the Ikelite DS-161, Sea & Sea YS-250, and Retra Flash, though with narrower beam coverage than all three. Mustard emphasized that guide numbers alone “can be very misleading because they simply tell us how bright the centre of the beam is” — the visual beam comparison showed the Z-240 had the narrowest beam coverage of the mid-tier strobes. The larger Seacam 150 (GN 22 with diffuser) and Subtronic 270 (GN 25 without diffuser) were a step above in both power and coverage ([4]).

Significance

Technical Specifications

FeatureSpecification
Guide NumberGN 24 (air, ISO 100)
Measured GN (with diffuser)GN 16 (Mustard 2017 test)
Beam angle100 degrees circular (native); 110 degrees with -0.5 diffuser
Flash modesS-TTL, Manual (13 steps, 0.5 EV increments), External Auto (24 steps), Nikonos TTL
Color temperature5,500K native
Batteries4x AA NiMH
Full-power flashes~320 (2,700mAh batteries)
Weight670g
Sync optionsOptical slave sensor; 5-pin Nikonos electrical connector
Focus lightBuilt-in LED (not aligned with flash axis — addressed in Z-330 successor)
Power (energy)Less than 100 W/s (Retra Flash at 100 W/s was “a bit more” powerful)

Accessories

The Z-240 developed a rich accessory ecosystem over its long production life:

Inon Official Accessories

Third-Party Accessories

TTL Converter Compatibility

The Z-240 was supported by all major third-party TTL converters:

Reviews & Discussion

Professional Reviews

Comparative Tests

Notable Users and Setups

Known Issues

Community Discussion

The Z-240 generated extensive community discussion throughout its production life and even after discontinuation:

Timeline

Legacy

The Z-240’s influence extends beyond its production years. Its physical design became the template for the Z-330 successor, which retained the identical battery compartment and control layout while adding substantially more power and features:

([94], [95])

The Retra Flash was designed from the ground up as a Z-240 upgrade path — matching its AA battery format, cable compatibility (both optical and Sea & Sea electrical), and compact form factor while delivering wider, softer light and more power in an aluminum body. Retra’s founding philosophy grew directly from experience building the LSD optical snoot for the Z-240. General Manager Oskar Zupancic explained: “Making the LSD taught us lots about existing light sources and different qualities of light. As underwater photographers we felt we could bring something new to the strobe market with, although it sounds slightly funny, a strobe fully focused on quality of light” ([96]).

As of 2023, used Z-240s remained some of the most commonly listed items in the Wetpixel classifieds, with photographers either upgrading to Z-330s or Retra Flashes while others sought them out as affordable, proven performers ([97]).


Sources

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  2. Wetpixel article, Nov 15, 2006: Dema 2006 Inon
  3. Wetpixel article, Nov 1, 2007: Dema 2007 Inon America
  4. Wetpixel article, Feb 1, 2017: Preview Retra Strobe By Alex Mustard
  5. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  6. Wetpixel article, Aug 30, 2017: Uw Technics Ships Ttl Converter For Canon
  7. Wetpixel article, Nov 5, 2016: Rt Electronics Releases The Turtle Ttl Strobe Trigger
  8. forum (forum)
  9. Wetpixel article, Feb 1, 2017: Preview Retra Strobe By Alex Mustard
  10. Wetpixel article, Mar 29, 2012: Retra Releases Light Shaping Device
  11. Wetpixel article, Nov 1, 2010: Reefnet Plans To Release Fiber Optic Snoot
  12. Wetpixel article, Oct 23, 2012: Retra Announces Pilot Light Enhancement Module
  13. Wetpixel article, Sep 20, 2017: Kickstarter Launch Ezknobs For Underwater Strobes
  14. Wetpixel article, Nov 7, 2006: Inon X 2 Housing For Canon 10d 20d 30d Preview
  15. Wetpixel article, Jul 30, 2007: Olympus E 410 Dslr And Pt E03 Underwater Housing
  16. Wetpixel article, Nov 17, 2008: From The Forums Frink On Seacam 150
  17. Wetpixel article, Jun 14, 2012: Inon Puts The Blue Back In
  18. Wetpixel article, Jun 2, 2010: Inon Announces Snoots For S 2000 Strobes
  19. Wetpixel article, Feb 17, 2019: Inon Ships Snoot Set For Z330 D200
  20. Wetpixel article, Sep 2, 2011: Review Light Shaping Device
  21. Wetpixel article, Mar 29, 2012: Retra Releases Light Shaping Device
  22. Wetpixel article, Feb 18, 2013: Field Review Retra Lsd Prime Snoot
  23. Wetpixel article, Oct 23, 2012: Retra Announces Pilot Light Enhancement Module
  24. Wetpixel article, Nov 1, 2010: Reefnet Plans To Release Fiber Optic Snoot
  25. Wetpixel article, Sep 20, 2017: Kickstarter Launch Ezknobs For Underwater Strobes
  26. Wetpixel article, Mar 11, 2011: Review Triggerfish Remote Slave Trigger
  27. Wetpixel article, May 24, 2011: Review Xit 404 Quad Ball Adaptor
  28. Wetpixel article, Aug 30, 2017: Uw Technics Ships Ttl Converter For Canon
  29. Wetpixel article, Nov 5, 2016: Rt Electronics Releases The Turtle Ttl Strobe Trigger
  30. Wetpixel article, Nov 6, 2017: Trt Electronics Ships The O Turtle Ttl Flash Trigger For Olympus
  31. Wetpixel article, Aug 30, 2017: Uw Technics Ships Ttl Converter For Canon
  32. Wetpixel article, Jul 18, 2012: Wetpixel D7000 Housing Review
  33. Wetpixel article, Jun 12, 2010: Canon 5d Mark Ii Housing Shootout
  34. Wetpixel article, Sep 16, 2008: Nikon D3 Field Review In The East Pacific Part 1
  35. Wetpixel article, Sep 17, 2008: Nikon D3 Field Review In The East Pacific Part 2
  36. Wetpixel article, Sep 18, 2008: Nikon D3 Field Review In The East Pacific Part 3
  37. Wetpixel article, Dec 18, 2013: Field Review Nikon D7100 And Subal Nd7100
  38. Wetpixel article, Oct 26, 2016: Field Review Nikon D500
  39. Wetpixel article, Apr 12, 2015: Review Canon Powershot G7 X By Alex Tattersall
  40. Wetpixel article, Nov 17, 2008: Review Nikon D700 In Subal Nd700
  41. Wetpixel article, Aug 19, 2010: Spider Crab Aggregation
  42. Wetpixel article, Feb 1, 2017: Preview Retra Strobe By Alex Mustard
  43. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  44. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  45. Wetpixel article, Jul 18, 2012: Wetpixel D7000 Housing Review
  46. Wetpixel article, Sep 16, 2008: Nikon D3 Field Review In The East Pacific Part 1
  47. Wetpixel article, Aug 30, 2013: Image Uk Blue Sharks
  48. Wetpixel article, Dec 9, 2007: Christian Skauge Norweigian Champion Underwater
  49. Wetpixel article, Jun 18, 2012: Unique Convict Blenny Schooling Behavior Captured
  50. Wetpixel article, Feb 1, 2017: Preview Retra Strobe By Alex Mustard
  51. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  52. Wetpixel article, Dec 21, 2017: Full Details Of The Inon Z330 Strobe Announced
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  54. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  55. Wetpixel article, Sep 20, 2017: Kickstarter Launch Ezknobs For Underwater Strobes
  56. Wetpixel article, Dec 21, 2017: Full Details Of The Inon Z330 Strobe Announced
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  67. Wetpixel article, Nov 7, 2006: Inon X 2 Housing For Canon 10d 20d 30d Preview
  68. Wetpixel article, Jul 30, 2007: Olympus E 410 Dslr And Pt E03 Underwater Housing
  69. Wetpixel article, Nov 1, 2007: Dema 2007 Inon America
  70. Wetpixel article, Dec 9, 2007: Christian Skauge Norweigian Champion Underwater
  71. Wetpixel article, Sep 16, 2008: Nikon D3 Field Review In The East Pacific Part 1
  72. Wetpixel article, Jun 12, 2010: Canon 5d Mark Ii Housing Shootout
  73. Wetpixel article, Aug 19, 2010: Spider Crab Aggregation
  74. Wetpixel article, Nov 1, 2010: Reefnet Plans To Release Fiber Optic Snoot
  75. Wetpixel article, Mar 11, 2011: Review Triggerfish Remote Slave Trigger
  76. Wetpixel article, Sep 2, 2011: Review Light Shaping Device
  77. Wetpixel article, Mar 29, 2012: Retra Releases Light Shaping Device
  78. Wetpixel article, Jun 14, 2012: Inon Puts The Blue Back In
  79. Wetpixel article, Jul 18, 2012: Wetpixel D7000 Housing Review
  80. Wetpixel article, Oct 23, 2012: Retra Announces Pilot Light Enhancement Module
  81. Wetpixel article, Feb 18, 2013: Field Review Retra Lsd Prime Snoot
  82. Wetpixel article, Dec 18, 2013: Field Review Nikon D7100 And Subal Nd7100
  83. Wetpixel article, Apr 12, 2015: Review Canon Powershot G7 X By Alex Tattersall
  84. Wetpixel article, Oct 26, 2016: Field Review Nikon D500
  85. Wetpixel article, Nov 5, 2016: Rt Electronics Releases The Turtle Ttl Strobe Trigger
  86. Wetpixel article, Nov 25, 2017: Sneak Preview Inon Z330 Strobe
  87. Wetpixel article, Feb 1, 2017: Preview Retra Strobe By Alex Mustard
  88. Wetpixel article, Aug 30, 2017: Uw Technics Ships Ttl Converter For Canon
  89. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
  90. Wetpixel article, Sep 20, 2017: Kickstarter Launch Ezknobs For Underwater Strobes
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  96. Wetpixel article, Sep 20, 2017: Field Review Retra Flash By Alex Mustard And Friends
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  98. Z-240 announcement (2006) (article)
  99. DEMA 2006 Inon booth (article)
  100. Inon X-2 housing preview — S-TTL compatibility (article)
  101. Olympus E-410/PT-E03 — Z-240 TTL compatibility (article)
  102. DEMA 2007 Inon America (article)
  103. Christian Skauge Norwegian championship — twin Z-240s (article)
  104. Nikon D3 field review Part 1 — twin Z-240s (article)
  105. Nikon D3 field review Part 2 — macro with Z-240s (article)
  106. Nikon D3 field review Part 3 — wide angle with Z-240s (article)
  107. Seacam 150 discussion — Z-240 comparison (article)
  108. Nikon D700/Subal review (article)
  109. Canon 5D Mark II housing shootout — Z-240 for macro (article)
  110. Spider Crab Aggregation — twin Z-240s (article)
  111. ReefNet fiber optic snoot — Z-240 support (article)
  112. Inon S-2000 snoots — Z-240 not supported (article)
  113. Triggerfish remote slave trigger review — Z-240 tested (article)
  114. Xit 404 Quad Ball review — used with Z-240s (article)
  115. LSD optical snoot review — Z-240 tested (article)
  116. Retra LSD commercial release — Z-240 mount (article)
  117. Inon color temperature conversion filters for Z-240 (article)
  118. Unique convict blenny — Z-240 strobes (article)
  119. D7000 housing review — Z-240 strobes (article)
  120. Retra PLE module for Z-240 (article)
  121. Retra LSD Prime field review — Z-240 tested (article)
  122. UK Blue Sharks — Z-240 by Amanda Cotton (article)
  123. Nikon D7100/Subal review — twin Z-240s (article)
  124. Canon G7X review — twin Z-240s (article)
  125. Nikon D500 field review — borrowed Z-240s (article)
  126. TRT-Electronics Turtle TTL trigger — Z-240 compatible (article)
  127. Retra Flash preview — standardized strobe comparison (article)
  128. UW Technics Canon TTL converter — Z-240 compatible (article)
  129. EZKnobs Kickstarter — Z-240/D-2000 compatible (article)
  130. Retra Flash field review — Z-240 comparisons (article)
  131. o-Turtle TTL trigger — Z-240 compatible (article)
  132. Z-330 sneak preview — Z-240 ceased production (article)
  133. Z-330 full specifications — Z-240 comparison (article)
  134. Inon Z-330/D-200 snoot set — successor ecosystem (article)
  135. Forum: Combining Z-240 and Z-330 (forum)
  136. Forum: Canon R5 UW Technics Z-240 (forum)
  137. Forum: Inon’s tragedy (forum)
  138. Forum: Z-240 Type 4 for sale (forum)
  139. Forum: Inon Z240 or Sea and Sea YS-D1 (forum)
  140. Forum: Z-240 vs YS-D2 beam performance (forum)
  141. Forum: MDX-D500 TTL with Z-240s (forum)