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Navigating the underwater wilderness

David Hall’s photographs of scenery and creatures off the coast of Canada in the Pacific Northwest portray serenity under the water, which belie the extreme challenges he faces to get his images.

“You’re photographing in water rather than in air, so it makes everything far more difficult,” he said.

For each shoot, Hall wears a dry suit, a neoprene body suit that covers all of his body but his head and traps air inside to keep him warm. Water temperature in Canada’s British Columbia typically ranges between 45 and 50 degrees Fahrenheit.

Hall typically takes just one camera with him in waterproof casing with a zoom lens. He also wears at least 40 pounds of lead to help him stay submerged, plus his scuba diving gear.

He has only one hour on a dive to shoot, and he can’t dive more than three or four times in a day to prevent nitrogen buildup. The deeper he goes, the more the pressure increases. The build-up of nitrogen during a dive can numb his judgment.

Often, he can only see a few feet in front of him.

The typically green hue of the cold water wipes out warmer colors, so he uses a strobe to capture the reds and oranges of marine life.

There are more particles in cold water than warm water, which means he must get within 10 feet of his subject rather than 100 feet as he would in tropical water.

“Under water, you measure in feet rather than miles,” he said.

Hall started photographing underwater in the late 1960s on a primitive waterproof camera, the Nikonos II. There was no way to check the camera’s focus other than by guessing the distance.

“It was often said if you could take a picture of something recognizable, then it was publishable,” he said about underwater photography in the ‘60s.

Hall took 36 flash bulbs and would have to change them out after each take. He couldn’t change the film underwater, so he would be limited to 36 exposures. Shooting digital with strobes means more shots from each dive.

Underwater photography started off as a hobby for Hall soon after he started diving. While an intern in medical school in the late 1960s, he took a camera with him to show others what he saw underwater and gradually it became more serious.

He began selling prints in the 1980s. Now a retired radiologist, he works full-time on his photography. His latest book, “Beneath Cold Seas,” highlights his work in the frigid waters of the Pacific Northwest.

Hall studied zoology in college. His coursework and diving experience enable him to easily identify most species he encounters.

At first, Hall took a technical approach to his photography.

“Before I thought of it artistically, I was mainly looking for things that were interesting scientifically that I hadn’t seen before,” such as rare species or new behaviors, he said.

Established nature photographers Eliot Porter, Douglas Faulkner and Christopher Newbert inspired him to look for more when shooting.

“I might follow fish around for a half hour or more, take dozens of photos and throw them out because the background isn’t complementary,” he said.

Hall is always ready to deviate from any dive plans he might set up.

“I might dive planning to photo seahorses and end up face-to-face with a whale,” he said. “I try to take advantage of whatever I find on a particular dive.”

- Lauren Russell, CNN