Underwater video light

What it means

Water absorbs light quickly, and it absorbs red first. A few meters down, reds fade; by 15 to 20 meters, footage turns blue-green without artificial light. An underwater video light is a waterproof lamp that puts that missing light back, revealing the true colors of coral, fish and divers, which no amount of white balance can fully recover once red is gone.

Unlike strobes used for photos, video lights shine continuously. They are rated in lumens, from around 1,000 for small action camera lights to 10,000 or more for professional setups, and are usually mounted on arms either side of the camera. They complement a red filter, which works only with ambient light in shallower water.

How it works in practice

Lights work over short distances, roughly up to one or two meters, because water swallows light on the way to the subject and back. Get close to what you film.

Mount two lights on arms angled outward, away from the lens, so they light the subject without lighting particles directly in front of the camera. This reduces backscatter.

Turn the light on for close subjects such as coral, fish and faces, and switch to a red filter or natural light for wide reef shots and open water where the light cannot reach anyway. A dive housing with a tray and handles makes the whole setup stable.

What to watch out for

Backscatter is the classic mistake: particles in the water lit by a light near the lens turn into a snowstorm of white dots. Angle lights out and avoid pointing them straight ahead.

Never combine a red filter with a strong video light on the same close subject; the result looks unnaturally red. Remove the filter when the light does the work.

Lights also change how wildlife behaves. Some animals flee bright light, and night dives with constant light can disturb them. Use the lowest power that works. Check the depth rating of every light, battery seals and o-rings before each dive, since flooded lights are a common and avoidable loss.