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UW Technics Announces TTL Converter for Canon Mirrorless Cameras in Marelux Housings
By Ian Bongso-Seldrup, December 2, 2022 @ 04:00 AM (EST)

UW Technics has announced a new optoelectronic TTL converter specially designed for Canon cameras in Marelux housings. New-kid-on-the-housing-block Marelux currently makes housings for the Canon EOS R5, EOS R5 C, and EOS R6.

The user-installable device can be used in both TTL and manual modes with various Ikelite, Inon, Retra, Sea&Sea, and Subtronic strobes, and high-speed synchronization (HSS) up to 1/8000s is supported with Retra strobes. Optical TTL and electrical TTL triggering methods are possible separately or simultaneously. The TTL converter fully supports Canon’s menu for external flash control.

The UW Technics #11080-HSS TTL converter is shipping now. Consult your local dealer for pricing.

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TTL Converter for Marelux underwater photo housings for Canon
Underwater Technics shares information about the newest TTL circuit especially developed for Marelux underwater housings for Canon photo cameras

Underwater photographer changes Aperture, ISO, Shutter Speed, Distance, and other parameters in a wide range, but the TTL flash control system instantly provides automatic adjustment of flash lighting intensity for each shot. It allows the photographer to concentrate the attention on the creative side of underwater shooting. TTL Converter is the heart of the automatic flash control system.

TTL Converter #11080-HSS was created by Underwater Technics Co. Ltd. (Taiwan) in cooperation and with the support of Marelux Precision Inc. (USA). The device, purposed for installation in Marelux underwater housings, provides automatic and manual flash exposure control for popular underwater strobes: Inon, Sea&Sea, Retra, Ikelite, and Subtronic.

Marelux factory currently produces the following underwater housings for Canon: MX-R5, MX-R5C, and MX-R6 with the housing line for Canon to be extended in 2023. TTL Converter #11080-HSS was specially designed for installation into all Marelux housings for Canon, independently of the camera model. The product was developed in 2022 by Underwater Technics and field tested with the Marelux housing MX-R5.

Easy User Installation

This device is a universal TTL board and it can be installed by the user into every Marelux housing for Canon. A user installation is very easy and takes 2 minutes. Just screw 2 bolts through the plastic frame and the product is ready for use.

Combined TTL Circuit

Product #11080-HSS is a combined circuit, consisting of Optical TTL and Electrical TTL system on a single board with both triggering methods available both separately or simultaneously. Fiber optical cable connection is supported as well as an electric sync cord connection. Dual fiber optical cables are supported with a powerful LED optical TTL output. Dual sync cords (Sea&Sea and Ikelite) are supported for electric TTL output.

Underwater Technics also supports M14 electric bulkheads made in Nikonos, Ikelite, and S-6 styles, compatible with Marelux housings. Also, there are available adapters for M16 and M24 thread, so electric bulkheads can be installed even into the M24 screw hole (purposed for HDMI connector on the housing).

So, the Marelux user has a variety of possibilities for building their own TTL system in the camera housing. System configuration is very flexible.

TTL Converter supports the most popular underwater strobes:

  • Inon Z-330, Z-240;
  • Retra Pro (including HSS functionality);
  • Sea&Sea YS-D1, YS-D2, YS-D3MkII (since December-2022), YS-250;
  • Ikelite DS-162, DS-161, DS-160, DS-125;
  • Subtronic Pro-270, Pro-160 etc.

The strobe type can be set with the onboard rotary switch.

High-Speed Synchronization (HSS)

Manufacturer of underwater strobes RETRA, in addition to the classic TTL and M modes, provides an interesting option, - HSS synchronization, this is the special flash operation available even at ultra-fast shutter speeds (available speeds - up to 1/8000 s).

Under HSS synchronization, the illumination occurs in a special time moment, and with a very long series of short flashes of 30 kHz frequency, it works during the entire time while a narrow strip of the open shutter moves along the frame. The flash intensity is regulated by changing the duty cycle of the pulses. Below is shown the comparison of normal flash and HSS flash:

Underwater Technics TTL Converter supports Retra HSS by its specially developed firmware HSS module. Users can switch to HSS synchronization via the Canon camera menu for an external flash, as this Canon graphical menu control feature is fully supported by TTL Converter.

Automatic ON / OFF switch

Underwater Technics TTL Converter #11080-HSS does not need an ON/OFF mechanical switch. The device activates automatically instantly when the user pushes the camera’s shutter release button, or touches any other camera controls. It also switches OFF automatically a few seconds later by camera command, if the camera is inactive for some time. This automatic power control saves battery life and highly increases the reliability and usability of the product. The product has an extremely low current consumption in standby mode and an incredibly long battery life (about 3 years in standby mode, or 65 000 flashes). The battery is a small cell CR2032 (2 pcs.).

Full support of Canon menu for external flash control

The Canon menu for external flash control is fully supported by the TTL Converter. UW Technics specially developed the firmware for advanced communication with the Canon camera menu. The camera sends menu settings to the TTL Converter and receives commands back from it, and then loads the necessary data to the camera. Hence, there is a two-way data communication protocol. This UW Technics TTL product has additional possibilities of working with the camera menu as information about the flash control settings is saved in the TTL Converter’s onboard non-volatile memory, even after powering down. This is a super comfortable feature for the user.

Using the Canon camera menu, the photographer can switch underwater the following settings, which are supported by TTL Converter firmware: TTL or M mode, 1-st / 2-nd curtain or HSS sync, +/- Flash Exposure compensation, Manual flash intensity adjustment (in M mode) in range 1/128….1/1, Evaluative or Average type TTL metering for flash, ON/Off flash and others.

Specifications of TTL Converter #11080-HSS:

  • Compatible underwater housings: Marelux
  • Compatible photo cameras: Canon
  • Compatible TTL strobes:
    • Inon Z-330, Z-240,
    • Sea&Sea YS-250, YS-D1, YS-D2 (China version), YS-D3MkII (since December-2022),
    • Ikelite DS-162, DS-161, DS-160, DS-125,
    • Retra Pro (including HSS),
    • Subtronic Pro-270, Pro-160.
  • TTL outputs onboard: 2 optical, 1 electric
  • HSS (High Shutter Speed sync) support: HSS up to 1/8000s (with Retra strobes)
  • Continuous shooting mode (CL / CH) support: yes
  • 1st / 2nd Curtain Synchronization support: yes
  • Switching “TTL / M” underwater: yes
  • (+/-) “Flash Exposure compensation” control underwater: yes
  • Switching power “ON/OFF”: yes (automatically, by camera command)
  • Battery type: CR2032 (2pcs.)
  • Current consumption (in standby mode): 0.01 mkA
  • Battery capacity (+20°C): 65 000 flashes, or 3 years in standby mode
  • Recommended Fiber-optic cable type: 613-fiber core (Nauticam #26217, HowShot 613L, Sea&Sea #50128 etc.)
  • Available Electric Bulkheads (optional accessory): Nikonos, S-6, Ikelite style
  • Dual Electric sync cord support (Sea&Sea, Ikelite): yes


Underwater Technics can be contacted via email or via Facebook.
Details of the products are available on the Underwater Technics website.



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