Cinematography Underwater

Color & Water: Underwater Light Properties
Coral reefs display the most impressive color combinations in the natural world. Photos and video bring it’s rich variety of colors and textures to the human imagination. I was shocked to hear that only two percent of the world population will see a coral reef. So video is important bringing the experience to the masses.

Light is altered by water, at times dramatically relative to air. Some color is absorbed or reflected by particles. The first affected color is red, the shortest wave length. Continuing around the color wheel; orange, yellow. Blue is the longest wave length in the color spectrum and the only color to penetrate deep into the sea. Eventually even blue is overtaken by the ocean’s depths leaving no light and total blackness.

On a perfect day: red is gone after 15 ft. Look at a color wheel and moving away Orange slips away after 30 ft. Yellow and violet are equally absorbed by 70 ft, they are equal in length and equal distances from blue. Then green the last hold out is lost by 85 ft. and blue by 100 ft. Below that threshold everything is shades of gray; eventual black. Using this hypo Black would be defined as the absence of all color.

Not even Black and White is as simple as black and white: In print the opposite is true. White is typically considered the absence of all color because a ‘blank canvas’ starts white.

Nearly all scuba dives below 50 feet reveal the familiar blue-green ambient. The human eye tends to adapt to available ambient and correct for it mostly because we perceive the correct colors in our brain. This is a psychological adjustment in perception of the warm colors. However when those eyes are on dry land the exact image is perceived as severely incorrect. Blue or green.

Photographers can use film emulsions; chemical reactions that affect the negative by manipulating the heavy cyan hue. But not many professional underwater photographers are using film. I recently shot an interview with Stephen Frink in his Key Largo Studio. His photos in my opinion are some of the best in the world. He’s shooting digital. No longer having to drag 6 camera down. Many photographers like working in the dark room; watching the image develop, doing the liquid Photoshop thang. Digital is very different, and its through the use of that program that I have any knowledge of color. Not an expert, but a user, among other things.

Problem: When an image is soupy cyan.
Let’s review for a moment: Red is the shortest; blue the longest. Shorter the wave quicker the absorption. Longer waves remain so everything looks… green or a little deeper blue.

The logic to this problem is: Long frequency equals less detail. Blues are always the dirtiest channel, closest to black. Open a Photoshop file, switch to the Channels tab (you must have ’show colors in channels’ selected in the preferences). Look at just the blue channel. Not much contrast. How much detail do you see? If you were shooting DV or HDV blue is going to be limited! It seems obvious to sample most where the detail is, in the SHORTEST frequency waves. The most often repeated color freq, Fool. Ever notice a 60Hz CRT monitor flicker in the corner of your eye? Graphics monitors are way faster in redraw for more detail and truer color. To this day some graphics professionals prefer CRT monitors.

In air, light is stable and simple. It can also be controlled with ease. Below the surface light is ever changing, always affected, then again it may not change at all. The surface and every drop between it and the subject, subject and the camera has a say in what gets reflected, what gets refracted, what gets absorbed, what gets through. What affect all this can have on the shot is still random.

This result is the beauty of underwater color in some shots. But to really see the colors of coral requires artificial light. Strobes give a blast of light for stills. Video requires artificial light to recreate perceptually correct colors. Even then the proper balance of Kalvins to Watts to figure the effective reach of the lamp(s) for a realistic product.

Many underwater shooters find it easiest to add color filters for color reproduction. Professionals do not use filters in this way because the down side is just as tragic. White balance must be performed; it’s just that simple. Make sure your camera can perform a white balance or has an auto tracking sensor built in. Keep in mind that these sensors are designed and setup for real world use, and even though the ocean is part of the real world I don’t believe that is what the engineers had in mind.

Underwater Cameraflyers don’t get second chances. It’s critical to understand not only camera equipment but also light properties in water. HDV is never a good choice for professional quality. Most networks won’t accept less that 4:2:2 sampled color because ALL underwater footage needs a degree of TLC in post. But the true colors of coral are there; waiting to be discover through a variety of techniques to achieve the desired look. Your video may become some of the best in the world, especially if mankind fails to respect and protect the ocean that provides so much.

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