Underwater Photography Begins Where Water Absorbs Light and Color

Light and Color Are Absorbed by Water, with Depth

The first thing to know about underwater photography is that water absorbs light.

Air weakens light a little too, but water is on another scale. And not every color weakens equally. The longest wavelengths — red — are lost first, then orange, then yellow, and what survives longest is blue and green. So the deeper you go, the more the frame drifts toward a single blue. A red fish photographs brown, then nearly black, for this reason.

The depth at which red starts to disappear shifts with water clarity, time of day, and the height of the sun. It is not something you can pin to a single number. Still, assume red begins to fade shallower than you expect, and you will fail less often.

There is an order to the fixes.

1. First, shoot in the shallow layer with the sun behind you. Shooting while the light still reaches straight through is the most reliable.
2. Push white balance toward the underwater side. A camera's underwater mode or manual WB recovers some of the blue cast. Lifting red in post is another route.
3. If that is still not enough, add light (below).

The auto white balance on phones and action cams sometimes cannot correct a strong blue cast. If a shot looks bluer than expected, suspect depth and light first.

Water Is Hazy. So Close the Distance

Water also hazes.

However clear it looks, fine particles drift in any water. The thicker the water between you and the subject, the more that haze stacks up, and the more contrast and color fall away. Shooting a subject 5 m away on land and 5 m away underwater are best treated as completely different conditions.

This is where one idea does the heavy lifting: rather than reaching in with a telephoto, get close with a wide lens. Reduce the water between you and the subject and the haze drops, and color returns. That underwater photography treats "go wide, get close" as basic comes largely from this.

When you use a light, watch for backscatter. When a light hits the particles suspended in the water, countless white dots can appear in the frame. This too shifts with the distance between light and subject and the angle of the light.

But getting close has limits. Push too near a creature and it flees, and there are distances you should not cross for safety and for the environment. The "reduce the water" idea matters, but not ahead of safety or care.

How to Add the Light You Are Missing

If light is absorbed, think about adding it — but in order.

First, use up the natural light. In the shallow layer, on a clear day, with the sun behind you, both color and brightness come out relatively honestly. The deeper you go and the later it gets, the more suddenly natural light becomes unreliable. Early on, just choosing these honest conditions changes the photos a great deal.

Next, white balance and filters. Underwater mode, manual WB, and a red filter all help pull back the blue cast within the range of shallow natural light. But once you go deep enough that the red light itself is gone, there is no red in the water to restore, and a filter can work against you.

Last, artificial light. For video, a waterproof light; for stills, a strobe. It recovers the color of a nearby subject, but if the source sits too close to the subject or aims too head-on, the backscatter from before increases.

At the entry stage, rather than adding light immediately, the order that is easier to handle is: first get a feel for color and distance in the shallow natural light, then add light when you actually need it.

Treat Sway and Buoyancy as Part of the Shot

Underwater, neither you nor the subject holds still. Waves and swell, your breathing, buoyancy — your body is always moving a little. The fish move too. Camera shake and subject blur both show more than on land.

So set shutter speed with a faster baseline than you would reason toward on land. The value has a range depending on light and subject speed, so no single number fits. But a setting that feels "maybe a little slow" is usually too slow underwater.

And the stability of your body points the same direction as the quality of the photo. Steady your breathing, hold neutral buoyancy, don't chase the subject. The calmer you can hold position, the less blur. Chasing a subject around underwater is bad for the photo and bad for safety.

An action cam shooting video has strong stabilization and suits the motion-heavy underwater world. In exchange, the strength of a single still frame is harder to make. Are you after a stopped frame, or motion within the flow? The gear you enter with leans toward different ways of shooting.

Choosing Gear — Decision Axes by Entry Point

What you shoot with changes both what you can capture and what to watch for. Compare on three axes — rated depth, operability, and how easy color is to correct — and the choice gets clearer.

• Phone + waterproof case/housing. The easiest entry. Suits snorkeling and shallows. Watch the case's rated depth, and note that physical buttons and the touchscreen get hard to use deeper down. Good for a first try.
• Action cam (GoPro / Insta360). Wide, strongly stabilized, and many models go straight into the water. Suits the motion of underwater. Mostly video-first; low light and fine color correction are often weak points. On format and mounts, Why GoPro and Insta360 Are Choosing MFT is worth a look too.
• Waterproof compact. A way into the shallows without an extra housing. When you want a balance of ease and image quality.
• Camera in a proper housing. Image quality and freedom are highest. In exchange, cost, weight, flooding risk, and operational effort all rise at once. No need to start here until you have decided to keep at it.

Whatever you pick, confirming first "how deep it can go," "can I operate it underwater," and "how easy is color to recover afterward" keeps you out of trouble in the field.

Decide Safety and Handling First

There is something to decide before shooting underwater: safety and handling.

First, underwater, safety comes before the photo. Do not postpone a breath, a surfacing, or a check of your surroundings for the sake of a good frame. This is not a platitude — in the water, a delayed decision carries heavier consequences than on land.

On top of that, decide the gear handling in advance.

• Prevent flooding. Before sealing, check that no sand or hair is caught in the O-ring. It is the most common source of failure.
• Use anti-fog. If the inside fogs with condensation, the frame goes milky white.
• Rinse well in fresh water afterward. Salt water especially wears gear fast if salt is left on it.
• Use a leash or float so you do not let the rig drift away or sink.
• Care for creatures and the environment. Don't touch, don't chase.

This preparation is not a passive chore. Keeping the gear in a state where you can happily get back in the water next time is the foundation for shooting over the long run.

Who Underwater Photography Suits, and Who It Doesn't

Underwater photography is not an extension of shooting on land.

It suits, I think, people who:

• would rather watch how light and color change in water than chase a flashy subject
• are comfortable with a style of getting close with a wide lens
• can hold a safety margin and stay calm and settled

By contrast, another choice may be better when you:

• want to reach a distant subject large with a telephoto
• want to carry as little flooding risk as possible
• want to prioritize reliable color and clarity in a short time

Underwater photography is not a situation that suits everyone. But for those it fits, it leaves behind light and color you cannot meet on land.

A Short Check Before Entering the Water

• Are today's conditions right for shooting the shallow layer with the sun behind you?
• Have you decided what to do about white balance?
• Are you set to get close with a wide lens rather than reach with a telephoto?
• Is the shutter speed fast enough to beat the sway?
• Have you checked the housing or case O-ring and the anti-fog?
• Do you have what you need to rinse in fresh water afterward?
• Have you put safety before the photo?

Underwater photography begins less with waiting for a special subject than with knowing how water changes light and color. Red disappears with depth, distance hazes, sway blurs. Keep those three in mind, start quietly in the shallows, and the first frame comes sooner than you would expect.

If you want to organize more broadly what to look at before the shutter, What to Notice Before Pressing the Shutter connects well. The thinking on distance and aperture makes a contrast with the land-side Aperture for Distant Scenes.