© 2002 Hartenberger Unterwassertechnische Geräte GmbH

Operating-Inst. flash-light
Spare part list flash-arm off-shore

High-Tech flash-lights

Conception with know how
Over 30 years of experience in underwater technology have gone into Hartenberger underwater strobes. Our concept for underwater strobes has led the industry for years.
A combination of proven traditional, and modern digital High Tech electronics have gone into our product development making them milestones in the industry for underwater strobe technology.
All the important components of our strobes such as the reflector, pilot light, cell packs and synchronisation cables have been developed as “plug-in” modular units. This allows numerous possibilities for technical details, functionalism and esthetical appearance.

Relying on our years of experience in manufacturing underwater strobes, enables us to give a 5 year guarantee against manufacturers defects on all the Aluminium, Plastic and Stainless Steel components. There is a 2 year guarantee on the electronics of the strobes.

Blitz-Test Zeitschrift "Unterwasser"


Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital

Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital



A centre piece of our strobes is the specially constructed Housing, with tried and tested applications over the years. The individual parts are turned on CNC lathes using marine aluminium alloy.
To provide the best surface treatment, the entire housing is coated with AHC (Aluminium Hard Coating). This results in a surface with much more chemical and abrasion resistance than a standard anodised finish. The chemical resistance of the AHC coating is even better than stainless steel and can be found in various industrial and military applications.
Despite the fact that the front and rear housing covers can be opened without tools, the sealing is provided by special compression and axial O Rings. We only use high quality Viton O- Rings.

The mounting point on the lower side of the strobe allows a multitude of mounts to be used (M6, M8 and M10 Threads).

The switches have double O Ring seals and provide years of reliable, trouble free use.

Due to the ergonomically positioned switches on the side of the strobe, the settings can be easily monitored and/or adjusted without any difficulties and your camera and strobe position underwater remains undisturbed when reaching for the switches in setting up your shots.




Choosing modern and over-dimensional components in combination with tested micro-processor electronics results in one of the most powerful and fastest recycling underwater strobes in the world.

The core of the Hartenberger strobes is the powerful and robust transformer. This allows a power rating of 625 watt/seconds and a recycle time at full power setting of 0,8 seconds !! (see technical specifications). The recycle time using lower power settings allows more than 10 frames per second (vital for fast motor drive use).

After recharging the condensers, the transformer switches off automatically. This reduces cell use and also avoids the prolonged radiation caused by the charging which disturbs some underwater life, causing them to flee.

The strobe ready signal appears on the switch panel of the strobe and in the viewfinder of the camera and easily visible. At the same time, a short acoustical signal (beep) can be heard.
The camera shutter speed is automatically set according to the synchronisation.

A special technical feature of our strobes is the extremely short flash duration hereditary in ring formed strobe tubes.
This is necessary because some Nikon cameras (i.e. F5, F100, F90...) require the entire light for a correctly exposed picture within 1/500th of a second.
Should the strobe require longer than this to achieve the correct exposure, then the camera will not send out the TTL cut off signal to the strobe!!!
In this case, the remaining energy is released as light and results in an uncontrolled, overexposed picture.


Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital








Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital


The right switch sets the following modes

  • OFF
  • ON without pilot light
  • ON with 100 % pilot light
  • ON with 50 % pilot light
  • ON with 25 % pilot light
  • Slave sensor with 100% pilot light
  • Slave sensor without Pilot light
  • Automatic Signal (for attention)
    In this positions, the following signals are possible and generated automatically:
    1. Pilot light with International SOS signal (3 x short, 3 x long, 3 x short)
    2. Strobe light with SOS signal (3 x short, 3 x long, 3 x short)
    3. Continuous Strobe every 15/30/60 Seconds at Full, -1 and -2 power settings

    The strobe can be used as a slave unit (strobe will be activated by a primary strobe) either with or without the pilot light.
    The slave sensor is not sensitive to natural daylight, but reacts very sensitively to the sharp light impulses from strobes. This allows the strobe to be used underwater at long distances from the primary strobe.
    The 6 manual power settings are available for the slave mode.

    A special feature is the TTL slave mode. In this mode, the amount of light which the slave produces is remotely controlled by and matched to the primary strobe!

Tue following modes can be set with the left switch:

  • TTL-Mode (automatic exposure control from the camera).
  • 6 Manual Power settings each of 1 f-stop.
The automatic TTL control is available for almost all types of camera and is built in as standard for the following makes of camera: Pentax, Canon EOS, NIKON F5/F4/F100/F, NIKONOS V and NIKONOS RS.
The electronics automatically recognises the type of TTL control from the connected camera.
Should there be an underexposure in TTL mode, an acoustical alarm will sound. A warning will also appear optically in the following forms: blinking ready light in the viewfinder, blinking pilot light and blinking red light on the switch panel on the side of the strobe.


Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital



Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital


The dimmable pilot light allows the user to adapt the strength of the pilot light to the ambient conditions. At reduced settings, energy is saved and the burn time is proportionally increased.

Spezial version without surcharge:
The pilot light can be controlled from the camera housing. This feature simply requires the appropriate switch on the camera housing.
The same switch can be used to trigger the strobe test mode. When this is activated, the strobe releases approx. 40 weak flashes within 2 seconds. This allows the photographer to judge the flood of light and establish any areas of shadow.

The beam of the pilot light is spot formed with a strong concentration in the middle point and a soft illumination of the surrounding areas. (This reduces the tunnel vision effect during night dives).
The pilot light is a plug in unit and is user replaceable.
The standard 6 V high temperature halogen Bulb is available rated at either 10 or 20 watts.
The plug in reflector unit with 95° beam as standard can be replaced within seconds (250/625 TTL).

A different colour temperature can be achieved by replacing the reflector. Reflectors are available with the following (approx.) colours.. 5500, 5000(standard), 4500 and 4000 Kelvin.

The crystal clear dome port can be replaced with a matt dome port. The matt port diffuses the light and generates a softer light from the strobe. The effect on the power output of the strobe is hardly noticeable.(approx-0.5/-1)

Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte 125 TTL digital - 250 TTL digital - 625 TTl digital  

If by mistake you try and take a picture without first switching on the strobe, an optical and acoustical warning will get your attention.

A discharge protection prevents the cells from an uncontrolled discharge. This is indicated by an optical and acoustical alarm.
The transformer is deactivated when the cells are nearly empty, it can however be activated manually for 3-5 more additional frames.
For safety reasons (ascent), the pilot light remains functional for a few minutes.
Should water enter the housing there is a sensor which immediately detects the smallest amount of moisture. For safety reasons, the condenser is immediately discharged (automatically generating a flash). After this discharge, the pilot light and all red LED lights will blink permanently and an acoustical alarm will sound.

Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte - Wechselakku

To remove the standard cell pack (Nickel-Cadmium) for charging, first unscrew the rear cover. The complete plug-in cell pack can then be removed or replaced with a charged pack within seconds.

The electronics are separated from the cell pack housing by O-Ring seals, this prevents moisture that has entered the cell pack housing from entering the strobe’s electronics.

Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte - Synchronkabel

The supplied standard synchronisation cable with the NIKONOS-V plug can be removed from the strobe allowing the slave mode without a cable dangling from the housing. This also means that a defective cable (expendable component) can be user replaced without sending the strobe to an authorised repair workshop.

A special feature first developed by us is the double seal NIKONOS Plug. The innovative positioning of the second O Ring provides 100% more safety and security in sealing. The plug’s thread is also kept dry whereas the original plug’s thread is surrounded by water. This prevents the vacuum which is generated when removing the plug, thus sucking water into the socket. Corrosion of the threads is also avoided.

Hartenberger Unterwassertechnische Geräte GmbH UW-Blitzgeräte - Blitzarm off-shore

Strobe arm off-shore
In Underwater Photography, the choice between a suitable or unsuitable strobe arm can mean the difference between pain and pleasure! The arm must be compatible with the size and the weight of the strobe being used. This match will provide the balance between ease of adjustment and a secure attachment.
Our off-shore strobe arm meets and optimises this criteria.
A special feature are the “O-Ring braked” joints that provide a unique level of comfort when using the arm. After loosening the lever, the joint still has enough friction to prevent it collapsing, the arm can however be positioned as desired. The arms are then locked by screwing the joints back tight.
This will hold the strobe in the desired position, even in the strongest currents and a raw boat trip.

The Strobe arm is made with neutral buoyancy




The printed curcuits boards, conductors in the electronic controls and all the mechanical components made of glass, aluminium and plastic have been precision manufactured in Germany using computer controlled CNC machining. The glass fibre reinforced plastic components are precision manufactured using 9 different moulds.

The most modern technology and high quality wokmanship of all the components combined in a quality controlled assembly and testing procedure make the Hartenberger flash-light the most precious and prestigous High-Tech under-water strobe available in the world today.

Blitz-Test Zeitschrift "Unterwasser"

Technical spezifications
  625 TTL digital 250 TTL hs digital 125 TTL digital
Power in Watt/Seconds 625 250 125
Rating above water approx 32 2/3 22 1/2 16 1/2
Angle of Beam from Reflector
95° 95° 95°
Re-Cycle time at full power with NC Cells (NMH +30%) 0.8 Sec. 0.3 Sec. 0.3 Sec.
Re-Cycle time at low power 0.1 Sec. 0.004 Sec. 0.1 Sec.
TTL Synchronisation analog NIKON/Canon/Pentax standard standard standard

High-speed TTL (Preflash speed for iTTL / eTTL)
(Converter in the camera body)


Converter in the camera body no more available

Converter in the camera body no more available
Manual power settings 6 settings each -1 f-stop 6 settings each -1 f-stop 6 settings each -1 f-stop
Slave activation (TTL and 6 x manual) standard standard standard
SOS Emergency Signal standard standard standard
Standard Colour Temperature (° Kelvin) 5000K 5000K 5000K
Reflectors 5500/4500/4000°K User replaceable User replaceabler (optional) non user replaceable
Illuminated switches standard standard standard
Pilot Light (Watt) with dimmer (%) 20W 25%/50%/100% 20W 25%/50%/100% 10W 25%/50%/100%
Strobe ready optical signal Strobe & Viewfinder Strobe & Viewfinder Strobe & Viewfinder
Strobe ready acoustical signal standard standard standard
TTL under exposed alarm optical/acoustical optical/acoustical optical/acoustical
Cell Low Charge alarm optical/acoustical optical/acoustical optical/acoustical
Synchronisation Socket standard standard standard
Plug In NMH Cell Pack
(optional as NC)
12V / 2.4Ah NC 12V / 2.4Ah NC 6V / 2.4Ah NC
Weight (above water) 3.0 kg (6 lbs. 9 oz) 2.5 kg (5 lbs. 8 oz) 1.9 kg (4 lbs. 3 oz)
Weight in Salt Water 0.0 kg 0.0 kg 0.1 kg (3.5 oz)
Dimensions in mm (inches) (Length x Diameter) 215 (8½”) x 139 (5½”) 220 x 119 225 x 99
No of frames at full power approx. 90 approx. 190 approx. 190
Pilot light (100%) incl. 36 Frames at full power approx. 60 Min. approx. 80 Min. approx. 60 Min.
Standard charger (LG) included/Charge time LG off-shore II / 2 hrs. LG off-shore II / 2 hrs. LG off-shore I/6 / 4 hrs.

Hartenberger UW-Flashlight Accessories Hartenberger underwater strobes 625
order code Type Description  
b125 125 TTL digital * incl. Cell Pack 6V/2.0Ah NC, charger off-shore I/6, synchronkabel 1498,00 €
b250 250 digital hsTTL* incl. Cell Pack 12V/2.4Ah NC, charger off-shore II, Synchronkabel 1798,00 €
b626 625 TTL digital
incl. Cell Pack 12V/2.4Ah NC, charger off-shore II, Synchronkabel 2298,00 €
* (high-speed) Pre-flash capable of digitale TTL-converter
Up date hs TTL Umrüstung 250 TTL digital (analoge TTL !) in 250 digital hsTTL (high-speed) Pre-flash capable of digitale TTL-converter 298,00 €
iTTL/eTTL (digitale TTL-converter) digital converter in the camera body no more available

Strobe arm  
order code Description  
armos Arm off-shore (Basis/Ausleger approx 20cm) 298,00 €
  Surcharge +10cm (max 50cm) 15,00 €
  Basisschiene (für NIKONOS V und div. Kompaktkameragehäuse) mit T-adapter 59,00 €

Accessories / Spare parts 125/250/625  
order code Description  
  Surcharge for second outlet 138,00 €
  Spare synchronisation cable NIKONOS 108,00 €

Accessories / Spare parts 125  
order code Description  
  Surcharge for automatic rapid charger LG off-shore II 78,00 €
  Spare Cell Pack 6V/2.4Ah NC 148,00 €

Accessories / Spare parts 250  
order code Description  
  Spare Cell Pack 12V/2.4Ah NC 178,00 €
  Reflektoreinheit 250Ws / 5500K 268,00 €
  Reflektoreinheit 250Ws / 5000K (standard) 288,00€
  Reflektoreinheit 250Ws / 4500K 308,00 €
  Reflektoreinheit 250Ws / 4000K 328,00 €

Accessories / Spare parts 625  
order code Description  
  Spare Cell Pack 12V/2.4Ah NC 178,00 €
  Reflektoreinheit 625Ws / 5500K 328,00 €
  Reflektoreinheit 625Ws / 5000K (standard) 348,00 €
  Reflektoreinheit 625Ws / 4500K 368,00 €
  Reflektoreinheit 625Ws / 4000K 388,00 €

  All prices include 19% VAT (german Tax). Rights reserved for technical changes
©Hartenberger Unterwassertechnische Geräte GmbH - Stand 01..2021