When I am teaching underwater photography workshops, I am always keen to avoid teaching people how to shoot one very specific photo in one very specific location at one very specific time of day. Instead, I prefer to teach people to assess a scene, understand it, and make decisions on strobe position and power that let them take the image they want.
The true measure of success for students from a workshop isn't whether they get good images on the trip — it's actually when they go on their next trip with no instructor, in a new environment with new scenery to shoot. If they can go on to capture great photos again, that is true success, as it shows an understanding of the teachings and an ability to calmly work through a thought process in any situation, coming away from the dives with great images.
Ask five underwater photographers how far apart their strobes should sit and you will likely get five different answers. Ask them why, and the good ones will not quote a formula. They will describe the scene they were shooting: the clarity of the water, the subject, the light, the shot they were after. That is the real skill in wide angle lighting. It is not a setting you dial in once and forget. It is a habit of reading a scene and responding to it, again and again, dive after dive.
A shot like this looks simple, but a huge amount of decision-making goes into delivering a shot where you can't notice the lighting.
Why Preset Positions Fall Short
Most guides to underwater lighting hand you a starting arrangement: strobes out at roughly forty-five degrees, arms raised above the housing, aimed just past the front of the dome and on half power. It is a reasonable place to begin, and every diver should know it. The trouble starts when that arrangement gets treated as the answer rather than a starting point. Water clarity varies enormously, from a rinsed-out blue water dive to a green, particulate-heavy bay. Subjects range from a pale, reflective fish to a dark, matte lava boulder to a diver in a black wetsuit. Ambient light shifts with depth, time of day, and surface conditions. A fixed setup that flatters one of these scenes will very often fail the next one, producing backscatter, blown highlights, muddy shadows, or a subject that simply looks flat and lifeless. The photographers who consistently come home with strong wide angle images are not the ones who found the perfect preset. They are the ones who stopped looking for one.
In a simple shot like this, the ambient light is first balanced, then great care is taken to ensure light only falls on the main subject and not the surrounding corals, isolating the subject from the background.
Reading the Scene Before You Shoot
Before you begin thinking about strobe position and power, you should first assess the scene. The first thing I consider is my camera settings, and this is largely dictated by whether I'm shooting into the sun or with it behind me. In other words, is the sun coming from over my shoulder and helping light the scene, or am I shooting directly into it? I will need to adjust my camera settings to accommodate this, as I want to ensure the color of the blue water background is correct first. I often get in the water, quickly look through my viewfinder, and dial in two types of settings — one for shooting with the light and one for shooting against it — so I have both ready for the whole dive. These settings do vary throughout the day, based on cloud cover, the angle of the sun, and other factors that are constantly changing.
But why does this matter for strobe power and position?
Imagine the sun is behind your subject: it's bright and creates a lovely halo around the scene. To manage that ambient light and make sure the blue water isn't too bright, we need to adjust our settings. Shutter speed is our go-to here — the faster it is, the less ambient light comes in, without affecting strobe power. But we are capped at 1/250 due to the sync speed of our flash guns, so that means we then need to start increasing aperture and decreasing ISO to get the right blues. When we adjust these two settings, they also affect our strobe power — lower ISO and higher f-stop numbers will decrease the strobes' effect on the finished image, so we need to start thinking about winding the power up to higher settings.
New shooters often assume you need higher-power strobes in dark conditions. It's actually the opposite — we need higher power on the brightest scenes, because we're ultimately trying to outpower the ambient light.
If we're shooting in darker, cloudier conditions, late in the day, or in deeper water, we have the opposite problem: we need to start increasing aperture and ISO, which means decreasing strobe power to compensate in the finished image.
Shooting into the sun and avoiding throwing any light onto the background here really isolates the subject — some extreme settings of ISO 50 and F22 here to manage ambient light.
Settings dialed in, it's time to assess the scene.
Before a strobe arm moves, start to consider the subject itself: how large it is, how reflective its surface is, how far away you need to be to fit it in frame, whether the subject is all on the same focal plane — meaning it's all the same distance from your lens — or whether the right side is closer than the left, whether the subject is flat on top, whether it needs lighting across the top or just the front, and whether you're working with a model in addition to the subject. All of this happens before your camera even enters the scene — remember, at this point you are just assessing in your mind and recognizing the key features you will need to be aware of before taking your shots.
Now, this might seem like a lot of variables, but it does become a process you can repeat time and time again. All you are really doing is studying your subject and deciding where you would like the light to fall. You're asking yourself which key parts of the subject are your highlights, and how you ensure you get light onto those parts properly.
The Variables That Actually Decide Where a Strobe Belongs
There is no single factor that determines strobe position. It is the sum of many, and a strong shooter is running through most of this list without even noticing:
Water clarity and the density of suspended particulate, which drives backscatter risk and dictates how far off the lens axis a strobe needs to sit.
Depth, and the amount of ambient light as you go deeper.
Distance from strobe to subject, and whether both sides are even.
Subject size, shape, and surface texture, since a soft sponge, a smooth fish scale, and a rough rock face all reflect light very differently.
Subject reflectivity, since silver baitfish, polished metal, and glassy eyes can blow out instantly if a strobe sits too close or too direct.
Direction and quality of ambient light, including sun angle based on the time of day and the intensity of sun from cloud cover.
Foreground elements in the frame, such as sand, silt on a wreck, or nearby coral, that can catch stray strobe light you did not intend to include.
Background elements and how much ambient blue or black you want to preserve behind the subject.
Where the subject sits in the frame, since a subject placed left of center calls for a different lighting emphasis than one placed dead center.
Lens field of view and dome port size, which change how wide the strobe light needs to spread to cover the frame evenly — for example, fisheye versus a WACP.
Whether the composition is close focus wide angle, with a near subject inches from the dome and a distant background, or a more evenly distanced scene.
Number of strobes in use, and whether you want a symmetrical, evenly lit look or a deliberately asymmetric, moodier one.
Strobe arm length and how much physical room exists to move a strobe head.
Thermoclines and haloclines and layers of mixed water density, which can bend or soften light in ways a camera settings chart will never predict.
Time of day and how much natural light is available to blend with strobe output.
The setting itself, whether open blue water, a reef wall, a cave mouth, or a wreck interior, since enclosed spaces bounce and trap light very differently than open water does.
The look you are after: a natural rendering close to what your eyes saw, or a more graphic, high contrast treatment.
Whether you are shooting verticals or horizontals — pointing the camera up toward the surface, for example, puts one strobe closer to the subject.
None of these variables matter in isolation. What matters is holding several of them in mind at once and letting them argue with each other until a strobe position falls out the other end. That is the thought process, and it is learnable, even if it never becomes fully automatic.
Managing ambient light here, and throwing the light forward on a slightly off-center subject — strobes higher in the frame and throwing the light forwards with high intensity.
A Practical Sequence for Working It Out
One advantage video shooters have is that when their lights are on, they can immediately see where the light is falling. Because of this, video shooters often adjust their lighting far more than still shooters do — they can see right away if the light is falling on a model's face, for example, and shoot accordingly. Strobe users don't have this advantage, so what you really need to do is put the strobes in the best place you think, based on the variables you've highlighted.
Start with an honest read of the scene, using the variables above. Then pick a starting position based on that read, take a single test shot of the subject, and review that image immediately. Do not judge that first frame on how it looks as a finished image; judge it on what it tells you. Bright, hard-edged spots usually mean a strobe is too close or too bright, as that side of the coral may be closer to your lens, so turn that strobe down. Backscatter and hot spots on either side of the frame usually mean the strobes are too far forward and are catching the edges of the dome, so move them backwards. Once you iron out these technical issues created by basic strobe positioning, it is time to move on to your more selective lighting decisions.
It is rarely a good idea to move your strobes further forward — you almost always want them behind the handles of your camera. Now you start to decide whether you need to move them up or down, wider or closer to the port, and whether you want them on the same power. Imagine you are close to the seabed and you see you have light on the sand in front of the subject, and you don't really want it there — it's time to move the strobes up higher and angle them a little straighter so you don't light the sand.
Imagine your model, in the blue water on the right side of the frame, looks a bit flat and silhouetted — it's time to raise the power on the right-hand side.
Imagine you have a hot spot on the left side — it could be because there is white coral on that side, or because the coral is closer to the camera there — then it is time to lower the power on the left side.
There are so many factors to think about, but in the end it is about looking at your image, deciding what you don't like about the light, and adjusting position and power to ensure you can have the light fall onto the parts of the frame that you would like it to.
Reassess constantly. A position and power combination that worked perfectly for one subject, at a specific time and place, might not work again, but you will learn a little something every time you go through the process, and each time you do it, things will become quicker and more intuitive.
Treat every new subject, every change in depth, and every shift in the water itself as a reason to run through the sequence again: read the scene, set a position, test, read the result, adjust position, then adjust power. With enough repetition, this stops feeling like a checklist and starts feeling like instinct, but the underlying process never really goes away, even for photographers who have been doing this for decades.
In an image like this there are many layers of complexity with the lighting; creating this black framing around the subject while still lighting the coral and the diver's face requires unique and deliberate strobe positions and powers.
The Real Skill Is the Habit, Not the Setup
There is nothing wrong with learning a standard strobe arrangement as a starting point, and I highly recommend you read the previous articles I wrote on this to have a fundamental understanding of the basics. Every shooter should have a basic starting point in their back pocket for the first few seconds of a dive, before there has been time to properly read the scene. The mistake is stopping there. Wide angle lighting rewards photographers who treat every dive, and often every subject within a dive, as its own small puzzle, one built from water clarity, subject reflectivity, ambient light, composition, topography, and your photographic vision, among the many other variables above. Solve that puzzle by observing first and adjusting second, position before power, and the images that come out of the water will look considered rather than lucky, no matter how the water, the light, or the subject decided to behave that day.