He is a creature of the night, a man who seeks an ideal in some of the darkest, most unlikely conditions.
"Late night, midnight, early morning, it's all good," Steven Christenson said.
That's why, on one recent night, Christenson crawled onto a ledge near San Francisco's Cliff House, armed with only a small camera, intending to take pictures of a giant one.
"I can't even count the number of people who come up to me in the dark and ask, 'What are you taking a picture of?'" Christenson said.
One of the keys to good nighttime photography is imagination. It isn't just about seeing the picture, but imagining how it might look after 20 seconds, 30, or two minutes, or all night.
"Since I like to take pictures of stars, you have to figure out how they will move in the sky because, as a human, you only see where they are. You have to imagine the arcs and paths they follow through," Christenson said
Even then, they may pack a few surprises. In one photo of the stars going across the sky, Christenson captured a meteor.
In real life, Christenson is a husband, father, and computer executive. But every man needs a hobby. Christenson has thousands of images.
Now, he's becoming famous for them. A once-a-year sunset shot at Big Sur, won him the astronomy photographer of the year award from the Royal Observatory.
But to ask Christenson for a favorite picture is impossible.
"Night photography is great because it's dark and the camera sees things you can't," Christenson said. "Like you can't see colors at night, but the camera can."
But the giant camera, on that particular night, brought its own set of challenges. Christenson had taken a picture a couple of years earlier of Seal Rock, on the other side of the building. But in the darkness, it's hard to even focus, hence his unusual set of tools, including a laser beam.
"Focus. You need a point to focus. Otherwise, the picture turns out soft, and usually that doesn't work," Christenson said.
After a series of trials, Christenson settled on an exposure of 30 seconds.
The final product is an eerie take on a familiar scene. The ocean, the Cliff House, and its giant camera, as we have never seen them before.
"I really like the colors," Christenson said.
Just another night on the prowl for a man who turns darkness into light.