Creative techniques in underwater photography definitely follows trends or fashions, and in most cases it is the use or invention of new tools or new uses for existing tools that sparks a new technique. It is also true to say that these fashions are somewhat cyclical, and that photographers often reinvent existing techniques to get distinctive effects. With that in mind recently, off-camera lighting has been described to me as the new snoot. The ability to vary the direction and source of external lighting presents a range of opportunities for exciting and different looking images. These range from radically backlighting subjects to adding light into areas that conventional camera mounted strobes cannot reach.

I mentioned above that it is often technical innovation that ushers in a new technique, and there is no doubt that this is the case. Of the three methods used to trigger strobes, two of them could be described as being of recent invention. The three methods are:

1. Using a long electrical trigger cable.
2. Using a long fiber optical trigger cable.
3. Using an optical remote slave trigger.

The first two techniques are relatively well established and pretty reliable. They carry the drawback of needing to carry long lengths of cable and the need to hide said cable in the resulting photograph, either by using camouflage, or by removing the cables in post-production.

Optical triggers have also been around for a while. Many current strobes actually have optical slave trigers built-in to them, and Ikelite have had an external Slave Sensor available for their Substrobes since the nineties. The problem with integral slave triggers is that in order for them to trigger reliably, they must be in line of sight with the command strobe, and this normally means that they are visible in the image too. This limits where you can place the strobes for best effect.

Reliable and sensitive optical slave trigger circuitry has existed for some time and is used extensively for (dry) cave photography. The problem was to find a way of housing these circuits for use underwater without compromising their performance. Wetpixel member Hedwig Dieraert has addressed this need with a new product called the Triggerfish. This small anodized aluminum unit houses an electronic slave trigger, and is connected to the slave strobe by a universal Nikonos 5-pin sync cable. It has no internal batteries, but draws power from the ready circuit of the strobe.

The Triggerfish is supplied with instructions and a small magnet to access its settings. It can be set to work in two modes, one of which triggers on the first flash of the master strobe, the other which ignores the first flash, but triggers with the second. This makes it compatible with master strobes that are working in iTTL. These settings are easily changeable by holding the supplied magnet close to the unit and monitoring the blink pattern of the two red LEDs to gauge which setting the unit is in.

The LEDs flash also continuously while there is a strobe attached, to give a visual clue as to which setting is active. I attached the triggerfish to an Inon Z240 strobe and had no difficulty in triggering the slave with either single or TTL master flash signals. For the purposes of this review, all the testing was done with Inon strobes; Hedwig has tested it with Sea & Sea, Ikelite and Subtronic as well. It is important to note that the Triggerfish cannot control the strength of the strobe’s output. This needs to be done using manual output adjustment.

Optical slave triggers work best in darkness, as they sense the difference between ambient light level and the flash of the master strobe. In darkness, this difference is at its greatest. Conditions for the testing were a combination of bright sunny weather, with quite high ambient light levels and gloomy days at greater depth.

To gauge how sensitive the Triggerfish is, I set up the triggerfish and strobe in an opening of an aircraft fuselage at my local dive site. I then took a series of images, moving away after each shot and using the airplane’s wing for a distance scale. The distance from fuselage to wingtip is 15 meters (45 feet.) The slave fired consistently (although it darkens as we move away from it due to its light being absorbed by the water.) This proved that the optical sensor in the Triggerfish is more than sensitive enough for anything we may need to do with it underwater.

Please note that these shots are purely to test the sensor’s performance. Practically, using a remote strobe at anything over 10-12 meters (30 to 36 feet) is unlikely to produce a good effect, except perhaps at night. This is due to the drop off in the slave strobe’s output as the light is absorbed by the water column.

I then tried to use the slave more creatively, placing the strobe inside the aircrafts cockpit, with the Triggerfish dangling through one of the windows. It is while doing this that I discovered how directional the trigger is. It is critical the the “eye” of the sensor points pretty much directly at the master strobe, if it doesn’t it tends to be unreliable. This in itself is not a challenge, just something to be aware of when setting shots up. Once aimed correctly, the trigger performed flawlessly.

I was using two Inon strobes in the cockpit, one firing from the Triggerfish, the other slaving off of it. The results were quite pleasing:

The Triggerfish I was testing was from Hedwig’s first batch, and doubtless improvements will be built-in to subsequent models. The cylindrical housing, whilst aesthetically pleasing, means that it tends to roll rather than stay put. It is slightly negatively buoyant, which means it will tend not to move, unless it is on any kind of incline. I would suggest “squaring off” two sides to make it more roll resistant. A further useful addition would be some kind of attachment eyelet or ring. Entering the water with multiple strobes is a recipe for a bad case of the danglies, which usually means losing valuable shooting time disentangling sync cables. Doubtless most people will fashion their own, but it would be great if there was a simple attachment point.

The Triggerfish is a simple, well-made and innovative item of equipment. It’s small size and weight, and the fact that it uses standard Nikonos sync cables makes it easy to have with you when a creative opportunity presents itself. It very adequately fills what was previously a significant gap in the tools needed for our creative arsenal. Once positioned correctly, its trigger is easily sensitive enough to be consistently reliable. I can’t see a continuing need for reels of electronic or fiber optic to trigger remote strobes.

The Triggerfish is available directly from Hedwig Dieraert and costs 120 euros plus 10 euros for world-wide carriage. The reviewer purchased one for the review. Many thanks to my other employer, Capernwray Diving for providing the venue.