INNER SPACE: Marie Tartar & Steve Eilenberg

The couple began diving in 1989 and underwater photography in 1996. Their photography spans the gamut from the planet's larger creatures, such as sperm whales and whale sharks, to some of the smallest, like the Wunderpus photogenicus, a creature right out of Tim Burton's Mars Attacks.

"In black water, there are small, translucent larval forms of life that come up from the deep at night," Tartar said. Shooting at night in the deep presents a set of unique challenges, requiring diving proficiency.

"The better diver you are, the better photographer you'll be," Tartar said. "You're on a life-support system, and you have to have excellent buoyancy," because if you drift to the ocean floor, you may stir up a cloud of sand and foul your studio.

Diving in black water presents the obvious challenge of finding subjects. To shoot at night, the couple positions themselves near a line dropped into the sea from a buoy; the line has lights attached. They also use their own lighting array, so that when something interesting comes into view, they can approach and photograph it.

Such a creature is a tube anemone larva, which lives in waters off the Philippines and rises from great depths. Nutrients in the water stick to the creature's "arms," which the organism licks. "As it slowly tumbles in the water column, I wait for a good body position and shoot," Eilenberg said. "Intense strobe light defines them and accentuates features and organelles that otherwise would go unnoticed."

Not all their quarry is so small. Tartar just returned from Argentina, photographing southern Atlantic right whales, an endangered species that was hunted extensively until the 1960s.

"Whales are simply too big to light with strobes (flash)," Tartar said. Much of that photography is done at or just below the water's surface.

The reward, they said, is in sharing images of creatures that few get to see.

"In the end, it's about showing people a hidden world," Tartar said. "A world that we value greatly, and everyone should value, that our planet depends on. You can't really appreciate or conserve something you don't understand. You can't value it if it's an abstraction to you. It's kind of a miracle what's in there, and we only know a fraction of it."

Eilenberg said he hopes their photographs help people realize how important it is to respect and protect the ocean. And he hopes that viewers are amazed by what they see.

"I'd love for some people to just have their mouths drop open and say, 'I can't believe this even exists on this planet. This is not a real creature, is it?'" Eilenberg said.