Underwater Photography Basics: Why Your Photos Are Blue and Hazy

Why do underwater photos come out blue?

Because water strips the warm end of the spectrum first. The Deep Ocean Education Project fact sheet, produced with NOAA Ocean Exploration, puts it in energy terms: colours with lower energy, such as reds, oranges and yellows, are filtered out quickly, while blue and violet light waves carry more energy and travel deeper. The Ocean Optics Web Book says the same optically: absorption by water is weak in the blue and strong in the red.

Divers meet this at ordinary recreational depths. PADI's diving physics page says red disappears first at around 5 m (16 ft). Ikelite puts the practical loss of reds and oranges in the first 9 m (30 ft), and says images go monochromatic beyond roughly 12-18 m (40-60 ft) without an auxiliary light source. The part that explains most ruined photos is distance, not depth: light is absorbed over any distance, depth or separation from your subject, so even in 1.5-3 m (5-10 ft) of water, distant objects carry no colour. Our scuba gear guides cover the rest of the kit.

Refraction shifts size and position on top of that. PADI gives the standard figures: objects appear about 25% closer and 33% bigger underwater. Your camera meets the same illusion through a flat housing port, which Ikelite describes as bending light rays and magnifying the resulting image. A dome port corrects that bending, and Ikelite says it captures about 25% more of the scene from the same distance, so wide scenes want a dome. A dark mask skirt cuts screen glare, one reason photographers choose them (see our dive mask guide).

The one rule that fixes most bad underwater photos

Take the water out of the picture. Ikelite states it as a rule in its housing manuals: the number one rule in underwater photography is to eliminate as much water between the camera and subject as possible, so get as close as you can, then use the zoom. The same manual gives the figure that ends arguments about strobe power: with flash, subjects beyond 1.8 m (6 ft) will not have much colour regardless of strobe power.

Angle matters nearly as much. The manual tells you not to shoot down on subjects, because they blend into the background, and to shoot straight on or up at a slight angle, using the blue water as a contrasting background. Direction changes colour too: Ikelite notes that an image's tint depends on depth, distance to subject and position in relation to the sun.

Ikelite's dome guide says a wide angle lens lets you get much closer to your subjects, and the images and video will appear sharper and more saturated. On a compact or an action camera your fins do that job.

Why your flash fills the frame with white specks

Those specks are backscatter: your own light bouncing off particles in the water between lens and subject. A flash sitting beside the lens lights that column head on. Ikelite builds a part into its compact housings for this one problem: a deflector that blocks and redirects the camera's flash, which the manual says also stops the built-in flash from creating backscatter in the image.

Getting the light off the lens axis is the fix. Ikelite's low visibility article gives the rule: get those strobes as far from the lens as possible and angled slightly away from the lens, which reduces backscatter by spreading out the light. Each strobe throws a cone, the cones should intersect in front of the lens, and the farther apart the strobes, the farther away that intersection.

In genuinely dirty water the same article reverses itself and moves the strobes in, pulling the crossing point closer to the lens. It is honest about the ceiling: in the equivalent of an underwater sandstorm, no strobe technique will hide all those little starbursts. PADI's Digital Underwater Photographer course lists avoiding backscatter beside using strobes and enhancing colour.

Strobe or video light: which one do you need?

A strobe fires a burst for one frame, a video light burns continuously. Ikelite's accessory notes describe the roles plainly: an external strobe adds colour to restore the warmer colours filtered out by the water, a second strobe eliminates shadows, and external video lights add colour in the camera's movie mode, with primary video lights colour balanced to provide natural tones.

A continuous light does one thing a strobe cannot. Ikelite's troubleshooting table lists not enough available light for the camera to properly focus as a reason the camera will not fire at all, and the fix is a focusing light or a strobe with one built in. Buy as a system: Ikelite says Sea&Sea, Inon and Nikonos strobes support manual exposure only on its housings.

Red filters and white balance: when each one works

Both rebalance light that still reaches the sensor, and neither invents light that has gone. Ikelite says it of the two together: they cannot be used to bring out colour that just isn't there due to lack of light.

A filter belongs in shallow, sunlit water. Ikelite describes its UR/Pro filter for tropical blue water as enhancing warm reds and oranges with available sunlight up to 24 m (80 ft), and says colour filters are in general not intended to be used with a strobe or a powerful video light. Filters are water-specific: GoPro's dive kit pairs red with blue water, magenta with green water and a snorkel filter with shallow water.

On white balance, Ikelite's own documents pull in different directions. Its housing manuals say to set white balance manually for each working depth, and to reset it when you fit a colour filter. Its article on manual white balance for stills prefers auto white balance in the water, with the tint fixed afterwards from a RAW file, because that tint moves with depth, subject distance and angle to the sun while you shoot. Both follow from the same physics: with RAW the correction is free later, and with JPEG or video the in-water setting is the only one you get.

Which camera settings actually matter underwater?

Shutter speed does two jobs: it freezes the subject, and it sets how dark the water behind the subject looks, because the flash lights the subject while ambient light fills the background. Ikelite says faster shutter speeds make the water column look more richly coloured and slower ones make it look lighter, and gives 1/125 to 1/160 s as a setting that works about 90% of the time underwater.

With flash there is a hard ceiling. Maximum sync speed is set by the camera, and Ikelite gives 1/200 or 1/250 s for most bodies; shoot faster and part of the frame comes back black. High speed sync is not the way round it: Ikelite says it dramatically reduces the guide number of the flash, making it virtually useless underwater, and the pulse train is devastating to certain components in a strobe.

Aperture and ISO follow from the shutter sitting in that narrow band. Aperture becomes both your depth of field control and your flash exposure control, which is why Ikelite's macro advice is to set the shutter around 1/125 s and adjust aperture as necessary. ISO buys light and pays in noise, which is why Ikelite's compact housing manual starts at ISO 200 with the flash forced to fill-flash. One line in that manual is worth memorising: miss the exposure dark, because an overexposed image is missing colour information which cannot be adjusted afterwards, while a slightly underexposed one still has colour.

Buoyancy is a camera skill, and a reef problem

The research does not say photographers touch the reef more often. It says their touches do more harm. Observers who followed 100 divers across 30 sites in the Philippines found 88% made contact with the reef at least once per dive. Cameras were carried by 55% of them, and camera-carrying divers accounted for 52.7% of all contacts, about their share of the group, with a contact rate per minute equal to divers without a camera. The outcome was what differed: contacts made with a camera accounted for the highest proportion of contacts which resulted in damage, 77.7%.

Green Fins, the UN Environment Programme initiative coordinated by the Reef-World Foundation, asks member operators to promote a strict no touch policy for all reef diving, and publishes a separate best practice sheet for underwater photographers:

One item on that sheet has been tested and did not hold. It asks photographers to take no more than five flash photos per diver of an animal, because excessive use of flash will scare and stress marine life. A 2019 study in Scientific Reports gave Western Australian seahorses roughly 4,600 flashes over 34 days, up to 200 a day at highest strobe power, and found no evidence that strobes change gross eye anatomy or basic retinal morphology, and no decrease in hunting time or feeding efficiency. Handling was another matter: manipulation, with or without flash, significantly increased movement and turning away. The authors recommend that divers avoid touching or pursuing animals rather than focusing on regulations on flash use that have no scientific basis. Both agree on the half that matters, hands off, which our buoyancy and trim guide covers.

• Practise buoyancy control and hovering before you dive with the camera.
• Assess the situation first, and position yourself and your camera without touching the reef.
• Learn to fin slowly backwards, so you can move off the reef without damaging it.
• Do not hold onto coral, or move or break it for a clear shot.
• Do not touch, manipulate or chase marine life, with hands or pointer sticks.
• Secure gauges and regulators so they do not trail over reefs, and keep fins out of the sediment.
• Be still, and do not fixate on one species, because guides may feel pressured to move marine life for you.

Housings, floods and fog on the port

Test the housing empty before the camera goes near it. Ikelite's manual says to immerse the empty housing in water first, and if any fogging occurs or droplets of water enter, do not install a camera: clean the main o-ring and retest. Clear housings let you check the seal by eye, looking through the back for the darkened area where the o-ring is compressed. If that black line is not even all the way round, reseat the back and look again.

The o-ring routine is short and easy to get wrong. Remove it, put a small amount of the maker's own lubricant on your fingers, pull the o-ring through them until it feels slick, and do not stretch it. Lubricant reduces friction, it does not seal, and excess collects sand. Ikelite warns that other brands can make its main o-ring swell so it no longer seals, that spray lubricants contain a propellant which can crack the plastic, and that a housing should go back for factory service every one to two years.

Fog inside the port is trapped humid air, not a leak. The camera produces heat, that heat condenses the moisture onto the port, and the fix is to close the housing in an air-conditioned room or vehicle and put one or two desiccant packs inside before each day of diving. Once you are in the water, wipe bubbles off the face of the port with a finger, because they produce soft focus spots. Afterwards rinse the exterior in fresh water and work every push button while submerged to flush out trapped saltwater.

How to get better pictures without buying anything

Work through this before you price strobes and arms; our gear cost guide shows where the budget usually goes first.

• Swim closer until the framing feels too tight, then ease back.
• Stop shooting downward. Get level with the subject or below it, and put open water behind it.
• Move whatever light you have off the lens axis: built-in flash off, deflector fitted if the housing has one, or a torch held out to one side.
• Shoot RAW and set the colour later. If the camera cannot, redo white balance at every working depth.