Cave Photography





If underwater photography is a small niche in the wide world of photography, cave-diving photography is its obscure foreign cousin. Challenges include taking enough light into very dark places, managing the risk of adding tasks to an already task-loaded technical dive and finding something to photograph when there's not a single colorful critter in sight. On the other hand, the crystal-clear water, mysterious darkness and lure of the unknown can be a fantastic canvas for creating unusual and captivating images. From my experiences, here are some tips and tricks for those thinking of taking a camera underwater while underground.
Light
Photography is the art of playing with light. In the ocean, wide-angle photographs catch the sunlight that filters down through the waves and weather. With the background illuminated by natural light, strobe lighting brings color and definition to the foreground. There are abundant creative options for mixing natural and artificial light sources to capture the underwater world — just look at the beautiful images being made throughout the world's aquatic environments.

When diving takes you to darker places, sunlight disappears from the equation. Despite what Hollywood would have you believe, the only lights underground are the ones you bring with you. Our eyes adapt easily to the dim environment, but camera technology is not yet quite as clever; powerful lighting is key to successful capture of cave-diving images. This is especially true when trying to photograph large and spectacular underwater chambers.

Underwater photographers know water filters out light, and divers see this on every ocean dive as we descend away from the sun. The practical application for photography is that strobe light doesn't reach very far. Depending on the strobe power and clarity of the water, the strobe flash may not reach subjects more than a few feet from the camera. In wide-angle reef photographs you can often see the transition where the colorful reef in the foreground turns to blue-gray coral in the background.

In reef photography, the way artificial light falls off with distance can be a useful tool for bringing the viewer's attention to the foreground subject. In caves, it works against the photographer. Without the less-detailed, ambient-lit backgrounds to provide context and scale for the object of interest, disembodied objects float in the black. Any subject farther away than the strobes' limited reach is lost in the darkness. The foreground subject could be anywhere, and conveying the beauty and grandeur of the space in which it floats is tricky.
More Light

On-camera strobes gently light the formations in McCavity Cave and trigger the strobes held by the divers behind.

The solution? More light! Getting additional lights in the right places is crucial, and in some caves strobe positioning makes more of a difference than total power output. Photographers who venture into caves with two big strobes attached to their cameras may be disappointed to see their photos lack depth. When using only on-camera strobes, all the light in the photograph comes from a single point (or two points very close together) beside the camera. This straight-on lighting arrangement flattens details and textures, removes shadows and diminishes the third dimension.

To overcome this, move strobes away from the camera. Off-camera lighting is where caves allow real creativity — the uniformly pitch-black cave environment means the photographer gets to choose which parts of the picture to illuminate and which to ignore. Light from multiple, separate sources brings back the third dimension and lets the viewer see both foreground and background.

Off-camera lighting opens up a multitude of creative choices. Additional strobes can be placed to backlight key features, outline the entrance to a tempting side tunnel or light your buddies' expressions as they check out the scenery. If your dive team carries strobes positioned like dive lights in their hands, the images will look more natural and familiar to those who have been cave diving. Or you can go for a Hollywood look, hiding strobes behind rocks to make glowing walls. The options are limited only by your gas supplies, battery life and buddies' patience.
Strobe Solutions

Hand-held strobes light the background of each cave and create a
glow in the hazy water in Engelbrecht’s Cave and Ag’s Dreamtime Tunnel,
Olwolgin Cave.
There are technological challenges in getting multiple strobes to fire in sync. The difficulties of shooting in complete darkness are obvious, but this is one area where darkness is a great bonus. Many underwater strobes have built-in sensors so they can be triggered by the flashes of other strobes or directly from the camera via fiber-optic cable. A flash from the strobe that's connected to the camera can trigger the off-camera strobes. The speed of light means the cascade of flashes moves faster than the camera's shutter, and all the strobes fire together. This can be tricky in daylight zones where sensors may be confused by sunlight flickering through the water. In darkness, however, sensors are much more sensitive to distant flashes of light and can be reliably triggered from farther away.

Built-in sensors are generally fixed to the bodies of strobes, and they may not always be ideally placed. Some strobes' sensors, for example, are embedded in the reflector, so if the strobe is facing a distant wall the sensor won't be facing the "trigger strobe" on the camera. This limits options for off-camera strobe placement because it may mean a strobe won't fire reliably when positioned as desired. Strobes that have omnidirectional sensors or allow use of a remote sensor on an accessory cord are a cave photographer's best friend.

Placing strobe sensors at the ends of cables allows them to be triggered after being hidden around corners. For example, you might attach a backward-facing strobe to your buddy's double tanks (duct tape works well for this), run the sync cord over his shoulder and position the sensor on the front of his harness. As he swims toward you, your on-camera strobes will light his face and the foreground, while the off-camera strobe will light the cave behind him. Now your photographs have changed from overexposed foreground rocks and ghostly diver faces floating in blackness to intrepid divers swimming through evenly lit tunnels.
Experiment with Care
Attaching a strobe to the back of your buddy's tanks requires care and attention from your buddy. Under the high-flow entrance at Devil's Eye in Ginnie Springs, Fla., the floor is littered with plastic tank-valve knobs from divers who came in contact with the roof. Even in low-flow caves, scratches on the rock in well-traveled areas show where divers' tanks commonly scrape against the roof. If your thousand-dollar strobe is the new highest point of your buddy's profile, it's wise to have a talk about the possible consequences of distracted diving before entering the water.

As the photographer juggles the technical and creative tasks that come from trying to get stunning photos with complicated equipment in an unforgiving environment, the buddy may also take on new responsibilities. As photogenic model and chief lighting officer, your buddy may also take the lead in navigation and safety. All these roles are important for coming home safely with great photos.
Why Photograph Caves?
Unlike the ocean, which is teeming with photogenic fish and other critters, caves are known for their lack of wildlife. Uninitiated divers question why on earth people would dive underground: "What are you going to see? Wet rock?" The short answers are "Yes," and "The wet rock is pretty spectacular." Photos are an easy way to explain the attraction of cave diving when they convey how it feels to float through massive darkness. The most important part of every wet-rock photograph is something that provides size and scale.
The Indispensible Buddy

Minimal on-camera flash in complete darkness is enough to trigger the
off-camera strobe, outlining the diver against the white limestone wall in
Kilsby’s Sinkhole.
Was the cave 10 feet across? Or a thousand? The easiest way for your viewers to gauge how impressed to be is for you to add a diver to the photo. And the ever-present diver with every photographer is his or her buddy. Just as it takes skill and effort to be a great photographer, it takes skill and effort to be a great model. It starts with gear selection (red drysuits are a favorite) and includes great trim and buoyancy for hovering and constant repositioning ("just slightly to the right"). The most important attribute is a lot of patience — floating midwater with an intrepid facial expression while the photographer fiddles endlessly with settings is not everyone's idea of a good dive.

Cave-diving photographers use wide-angle lenses to capture the whole cave when they are close enough to throw strobe light on the subject. These lenses tend to distort the edges of the picture, bending straight lines. For most setups there is a very small sweet spot for models that is between 3 and 10 feet away from the camera. This is far enough away for the model to be normal-shaped and close enough for the strobe light to reach him. Experienced models know this zone and move through it very slowly, allowing the photographer time to focus and recompose as necessary. Focusing in the dark will require either a dive light pointed at the subject (preferably not at the subject's eyes) or a focus-lock function on the camera.

Beyond modeling, the cave-diving buddy is often responsible for one or more off-camera strobes. These may be mounted on equipment, increasing the profile and requiring extra care, or handheld, requiring an extra hand. Off-camera strobes provide that essential third dimension of light. On the other hand, an off-camera strobe pointed directly at the camera at close range will ruin an otherwise perfect picture. A model who can hold the strobe at the perfect angle in relation to the rock structure behind him (without looking) while hovering motionless in the sweet spot for the lens and smiling for the camera should be applauded for his skill.
Focus on Safety

Crystal-clear water, multiple off-camera strobes and great diving skills from buddies showcase the rock formations in this tunnel in Tank Cave.

Cave diving is a sport that already involves extensive task loading. As divers move through a cave they need to calculate and monitor their air supplies, consider mounting decompression obligations and navigate a maze of passages. Surfacing requires a long swim in the right direction, and a quick ascent is not an option when there's a roof in the way. Cave divers carry redundant equipment in case of gear failure, and all this takes brainpower to manage. Taking photographs on a cave dive adds exposure calculations, strobe positioning, image composition, maneuvering a large camera rig and more to this mix.

Before adding all these tasks, cave divers must be proficient and comfortable in their diving. After adding so many tasks to the list, it makes sense to spread the load among the brains present. While each diver must monitor his own air consumption and be ready to call the turnaround, buddy pairs might agree before a dive that the nonphotographer will periodically signal for both divers to check and communicate their gas supplies before continuing. This regular reminder can free the photographer to immerse himself in the hunt for the perfect picture. A trusted and experienced buddy enhances both the photographs and the experience of taking them.

With all these essential roles undertaken by the nonphotographers in the group, it's important for photographers to avoid prima donna behavior. In the end, you and your friends are most likely diving together for fun. If the diving becomes less fun because of your photographic demands, you might end up with fewer friends. Be nice to your models, buy them beers now and then, say thank you, and share the photographs of them looking cool underwater.

Beyond the basics of lights and models, there's a whole world of great cave-diving photography. Darkness and crystal-clear water can be used to produce creative images that can't be taken anywhere else. Caves offer a more controlled environment than the ocean and allow for experimentation — free from worries about such things as being bitten because you set down a strobe on a well-camouflaged critter. Take advantage of these unique characteristics, and showcase the beautiful world below our feet. Above all else, dive safely.

© Alert Diver — Fall 2012