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3 Common Light Challenges in Underwater Photography

3 Common Light Challenges in Underwater Photography

Written by Leisure Pro Staff
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Published on August 29, 2017

Underwater photography is a fascinating hobby that seems like an easy switch for any experienced photographer. However, underwater photography has a few challenges that are unique to the environment and require a little adjustment to get the same quality of photos you may be used to. Just as with photography on land, it is important to understand the role of light in underwater photography in order to correctly compose your images. Let’s take a look at three common light challenges in underwater photography.

Refraction

Light bends as it passes from one medium to another in a phenomenon known as refraction. Refraction occurs when light traveling through water passes through the glass and air of your underwater camera, causing objects to appear approximately 25 percent larger and closer than they really are. Understanding this effect is important especially for cameras with autofocus features, as refraction can make it difficult to focus properly on the subject, leaving you with blurry images.

Underwater cameras with an infrared autofocus assist will work underwater, but those with laser rangefinders will have trouble focusing and produce blurry pictures. Ensure your camera’s lens always focuses at infinity or use a camera with a manual focus setting. Keep this 25 percent magnification in mind when composing your shots to avoid distortion and blur.

Light Absorption

Water is a great natural light filter, absorbing a substantial amount of light traveling through it the deeper it gets. A general formula for light loss underwater is for every 10 meters of depth, half the light is lost. So at a depth of 10 meters, you have 50 percent of the light you had at the surface, and just 25 percent at a depth of 20 meters, etc.

Your available light will not always be the same, however — it will change depending on the time of day. It is generally accepted that the best hours for shooting underwater are between 10AM and 2PM. This is when the sun is directly overhead and the water’s surface is reflecting the least amount of its light.

Weather also plays a role in your available light. If the conditions are stormy, choppy water will significantly impact the light conditions underwater. Water clarity obviously has a lot to do with how much light you’re getting on your subjects as well. It’s ultimately best to stay within 0-10 meters if you plan on shooting with natural light. Any deeper and you’ll definitely need a strobe to illuminate your subjects.

Color Absorption

Perhaps the most frustrating light challenge is color absorption — photos displaying no hues but blue or green. The reason for this is that the hues of yellow, orange, and red are emitted by short wavelengths of light that are quickly absorbed in water and absent at depths below 10 feet. Blue and green come from significantly longer wavelengths, reaching much further into the deep. At 80 feet, blue is the only color left before everything turns black.

Use of color-correcting filters is the most common and inexpensive way to address dull colors in your images. It is important to remember that filters can only enhance the colors present in the available light; they cannot add colors where there was not enough light to illuminate them. And the filter itself reduces the amount of available light as well, so they’re best suited for very shallow waters.

A strobe is the second most common way to address color absorption in underwater photography. Most strobes have adjustable settings that allow you to control the light output for each image, giving you the opportunity to create the perfect light every time. Getting close to your subjects will reduce the distance that the light has to travel underwater, increasing the efficacy of your strobe unit.

Leisure Pro Staff

Leisure Pro Staff

Marketing Director for LeisurePro