Tips for shooting Mr. Big in open water.
It has often been said that the open-ocean environment is a desert; sea life is most commonly found on reefs, in benthic regions and along coastal areas. The open ocean, or pelagic zone, most believe, is simply devoid of life. In reality, science knows little about pelagic zones. Open-ocean environments make up 95 percent of the volume of the sea, yet less is known about this region than all other oceanic regions combined. It is aptly called a "blue frontier," but it is hardly devoid of life.
Photography in the pelagic zone requires a pioneering spirit. There is never a guarantee of finding subjects, and even if subjects are found they may not provide many photo ops. For those willing to endure endless days enveloped in blueness, however, the rewards can be off-the-scale. Almost any animal in the sea can be a photo subject, including marlin, tuna, sailfish and even whale sharks. Finding them may take a bit of research and require a lot of time at sea, but the high-energy encounters you will have when you find your subjects will ensure that the memories of uneventful days fade quickly.
Some of my best blue-water encounters have occurred while free diving. The unencumbered freedom combined with the quietness of using only a mask, snorkel and fins is often the key to getting close to pelagic animals. Although wonderful blue-water photos can be produced while using scuba or rebreathers, developing your free-diving skills will serve you well in this pursuit.
As with all underwater photography, you will want to get close to your subject so that it does not become lost in the background. This is especially true when photographing animals that have evolved bodies designed to blend in with the water. You should also try to compose the image to show the animal's face, especially highlighting the eyes. Expose for the background water rather than for the subject itself: If you meter the water behind your subject, the resulting overall image should be properly exposed. Depending on your personal photographic style, you may wish to meter the background water and then reduce your exposure by half a stop or more to create a more saturated backdrop. This works especially well if a strobe is used to bring out some of the detail in your subject.
Becoming a "blue-water pioneer" and documenting these elusive animals with your camera will likely result in one-of-a-kind photographs. And remember, if it were easy, everyone would be doing it.
Blue-Water Shooting Tips
Select faster shutter speeds. Many pelagic animals are fast swimmers; unless your strobe will truly "freeze" the animal's motion, you will need a shutter speed of at least 1/125th second to accomplish this.
Try to position the sun at your back. It may not always be possible to get in the best position when photographing fast-moving animals, but try to be aware of the sun's position. If kept behind you, the sun will help to light the animal, especially in relatively shallow water.
Use one wide-angle strobe this can make a world of difference. Blue-water animals often get lost in a background of the same color. A pop of strobe can add sparkle that will show detail and separate the subject from the blue backdrop.
Beware of reflectivity. Many pelagic fish are extremely reflective. Using flash on these animals is like shooting into a mirror, and it is easy to overexpose. Remember to use a lower setting on your strobe than you normally would at the given strobe-to-subject distance.