Life just a few metres below the surface of the sea is unlike anything you’ll see on land. This creates amazing photo opportunities. Image making underwater, however, introduces a whole raft of challenges.
Most of the challenges with underwater photography can’t be easily overcome with technology; modern underwater photographers encounter many of the same issues that faced Jacques Cousteau. First you must be a competent diver in order to even get in a position to take photos. Then you must be using dedicated gear that can operate at depth. You must overcome the effects water has on light transmission. All the while, you must also be thinking about all the normal concerns of photographers like exposure and composition.
Underwater photography isn’t easy, but the pictures are fantastic! In this tutorial you'll learn about the main things to consider when you're starting out in underwater photography and how to get prepared.
Water and Light
Water is almost 1000 times denser than air. This density radically affects the transmission of light. Any photo taken underwater will have a lot less colour and contrast compared to a photo taken in air. This is not because underwater objects lack colour, but due to the diffusion, diffraction, and absorption effects water has on the light.
Light is absorbed as it travels through water. The red end of the spectrum (the longest wavelengths of visual light) is affected first, and the amount of red light available is drastically reduced within a few metres. This means that everything underwater has a blue or green colour cast.
The determining factor is distance, whether vertical or horizontal. The deeper underwater you go the more pronounced the colour cast, and similarly, the further the distance between the subject and the camera, the greater the blue-green cast.
As well as reducing colour and contrast, there is also a loss of overall light levels. When photographing underwater, unless very close to the surface, you will be working in a low light environment. There are a number of factors that determine how bright the ambient light will be including depth, water clarity, sun position, time of day and where you’re diving.
Besides the basic technical complexities of working underwater, the biggest challenge to making images is the effect water has on light.
Learning to Dive
Before even considering underwater photography, you need to know how to dive. The better you are at diving, the better you will be at underwater photography. The greatest underwater photographers working today, such as David Doubilet and Brian Skerry, not only have an exceptional creative eye but are extraordinarily competent divers. Doubilet alone has well over 10,000 dives.
"If you can’t control your buoyancy, you can’t get good pictures.”—Darryl Stansbury
Learning to dive is easy and fun. There are a number of training organisations, the most popular being the Professional Association of Diving Instructors (PADI) and Scuba Schools International. There are dive centres around the world that offer either PADI or SSI certification courses.
An introductory dive certification will teach you the basics of diving, dive safety and equipment maintenance over about ten dives. It will also help you realise whether or not diving is for you.
Darryl Stansbury, the diving instructor who certified me, says, “the most important skill for an underwater photographer to develop is buoyancy control. If you can’t control your buoyancy, you can’t get good pictures.” He reckons it takes around 30 dives before people begin to get a real feel for controlling their buoyancy. If underwater photography is something you seriously want to pursue, then investing in enough dive time to control your body underwater is crucial. Darryl recommends diving without a camera until you have your buoyancy “dialled in”, otherwise you’ll just be distracted.
The Gear You Need
Jumping into the ocean with your precious DSLR in hand hoping to take some photos of the fish can only end badly. To get underwater photos you need to use an underwater housing to protect your camera.
You can get underwater housings designed for most modern DSLRs. If you shoot with a Canon or Nikon camera then in all likelihood someone has manufactured an underwater housing for it. The big problem is cost; an underwater housing from a reputable brand like Aquatica or Nauticam for my Canon 5D MKIII costs more than my camera. As well as the housing for the camera, you also need a different port for each lens. Depending on what lens you want to use, this can easily add another thousand dollars onto the price tag. If you are serious about underwater photography then this is an investment that you may choose to make, however if you are just getting started, it’s almost certainly not worth the cost.
Instead, there are cheaper, dedicated underwater cameras that Darryl recommends as a starting point. Sealife manufacture a number of cameras that are aimed at amateur underwater photographers. There are a number of compromises, such as a smaller sensor size and no ability to shoot RAW images, but they are well designed and easy to operate underwater. They also take decent pictures and, as a way to learn underwater photography, are perfect.
The Wirecutter has a long gear guide on underwater photography and they make a couple of interesting recommendations. For people interested in videography rather than photography, they suggest starting with a GoPro action camera. The stock housing the latest models come with is suitable for recreational diving depths and the video quality is great. For photographers, their recommendation is to build a dedicated underwater rig around either a good point and shoot—their pick is the Sony RX100 MKII—or a mirrorless camera. While still a significant investment, a dedicated set up will normally be cheaper than trying to adapt your DSLR.
Protecting your camera, however, is just the first step. An underwater housing does nothing to overcome the light limitations of shooting underwater. There are two main solutions: off-camera lighting and filters.
Off-camera lighting, whether as a flash or a continuous video light, is the best as it helps deal with both colour and contrast problems. If a flash is the main source of light, the distance between the subject and the flash becomes the main determining factor in the quality of light. Obviously you can’t just bring a speedlight underwater, you need to use a dedicated underwater flash or video light. Most underwater housings—including the Sealife cameras recommended by Darryl—have the ability to attach one or two lights on adjustable boom arms. The arms are important as water is often filled with particles that will create backscatter if the flash is on the same axis as the camera.
The other option, filters, are better for videography than photography. A red filter compensates for the colour problems you get when shooting underwater by removing some of the blue light. This creates a more balanced spectrum of light that hits your sensor, but it has the unfortunate additional effect of reducing the overall amount of light, often by a stop or even two. This can mean drastically reduced shutter speeds. For video this could be acceptable, depending on the situation, but it may not work for photography.
Image Making Underwater
Like gear selection, the main extra considerations when shooting underwater are about overcoming the limitations of the light. Things like exposure and composition are just as important as they are on land and can be handled in the same ways.
All the issues with shooting underwater come from the underwater part of the equation. The less water between the photographer and the subject—and the light source and the subject—the better the resulting images. Thus, the most important thing is to get close, then get closer. Light quality decreases exponentially with distance so the further you are from your subjects, the worse your shots will be. Some photographers recommend never being further than a metre, however, if you are just starting out, this may not be practical. When shooting underwater you should get the camera and light sources as close to the subject as is feasible.
If you are close to your subject—and you should be—you need to use either a macro lens or a wide-angle lens for detail or wide shots respectively. Most other lenses will either be unable to focus correctly, or won’t capture enough of the scene for a powerful image. Lenses with focal lengths above 100mm or below 20mm on a full-frame 35mm camera are among the most popular with underwater photographers.
With a dedicated underwater rig, the majority of camera functions should be mapped to a button you can access. Even still, changing settings 30 metres under the sea is a lot more awkward than setting them before you dive. Before getting in the water, dial in the base settings you think you’ll need. Shooting in aperture priority mode can make this easier. What shutter speed, aperture and ISO you use will depend a lot on your gear, dive site and what you plan to photograph. Close-ups of a reef at five metres require very different settings to wide shots of sharks at 40 metres.
One way to make post processing easier is to get an accurate white balance while you’re in the water. A white or grey waterproof slate is easy to get a good white balance reading off. If you are shooting RAW, this isn’t as important, however if you are using a camera from a manufacturer like Sealife that only shoots JPGs, then in-camera white balance is crucial. Fortunately, dedicated underwater cameras make it easy to manually adjust it so it’s correct.
Recovering colour, contrast and reducing backscatter are some of the unique issues that water creates.
There are no special tools for post-processing underwater images. The majority of underwater photographers use Adobe Photoshop and Adobe Photoshop Lightroom. In Photoshop, adjustment layers like Curves, Color Balance and Hue/Saturation are the best for reintroducing contrast and colour to the scene. In Lightroom, the tools in the Basic and Hue/Saturation/Luminance panel will have the same effect.
If you’re shooting with a flash underwater, even if it’s off-axis, some of the particles floating between your camera and your subject may reflect light back. This is backscatter, and it shows up as white dots throughout the frame. If you or another diver in your party has disturbed the sand on the bottom it’s more likely to occur. The Spot Healing tool in Photoshop or Lightroom is perfect for getting rid of it.
As well as reintroducing colour and contrast, the same considerations you normally make when post-processing are important. You can use techniques like dodging and burning, sharpening, and retouching techniques to remove distractions in your images.
Underwater photography is a fun but challenging area of photography. The effects water has on light transmission reduce the amount of colour and contrast in your images. At every step of the shoot, you must work to overcome these limitations.
Before even considering underwater photography, you need to know how to dive. An organisation like PADI or SSI offers international certifications. If you want to be a good underwater photographer, you need to be a great diver. Dedicating the time necessary to develop skills such as buoyancy control will go a long way towards improving your underwater photography.
Underwater photography gear is expensive. Professionals use the same DSLRs as other photographers, however housings and ports can cost more than the original cameras. A dedicated underwater camera, either a less-expensive model from Sealife or GoPro, or a self-built mirrorless rig can be a better entry point than trying to bring your main camera.
When you’re shooting underwater you need to get as close as possible. A wide-angle or macro lens will give you the best images from that position. Artificial lighting will also increase the quality of your images.
Before you start taking photos, it’s important to have your settings dialled in. Adjusting them can be done underwater but it is more awkward. Set base settings for your situation and planned subjects before you start diving. As soon as you’re in the water, set a manual white balance.
Post processing underwater images is all about bringing back colour and contrast. The usual tools in Photoshop and Lightroom are perfect for doing it, you just might need to be a little more heavy handed than you are with your normal photos.
As with every form of photography, it’s important not to throw out the basic rules. A well exposed and composed image is crucial. That you’re taking an image underwater should not distract from this.