Not too many years ago Harold Davis was camping out in the Sierras, looking up at the stars above the sequoias and thinking that he'd never really seen a photograph that came close to capturing what he was seeing.

How would I go about taking that photograph, he wondered.

It took a while, but he figured it out.

"My first efforts were awful," he says. "Intuitively, what you think you should do when looking at something very dark is boost the hell out of the ISO." Actually, the opposite is true; all save one of the photos you see here were taken at ISO 100. It's exposure time, not ISO, that's a key to night photography.

Starting with trial and error and building on growing experience, he worked out some general exposure guidelines and starting points for his night images. For ever-popular car light trails, exposures of eight to ten seconds; longer if you like your light trails to look more solid. A good starting point for street scenes and cityscapes: 30 seconds. Landscapes with star trails call for at least three or four minutes, but for pronounced "as the earth turns" trails, figure 20 minutes to hours in length.

But as you approach hours, noise becomes a huge issue. To solve the problem, Harold applied an astronomical photography technique. His photo, Edge of Night, is the result of a combined exposure time of about an hour, but instead of shooting one hour-long, noise-building image, he shot 20 three-minute exposures and stacked them in post production.

Equipment plays a key role in Harold's night photography. A sturdy tripod goes without saying. Then, because 30 seconds is the longest shutter speed most cameras allow, Harold uses a Nikon MC-36 Multi-Function Remote Cord and the camera's bulb function to keep the shutter open for as long as he chooses. The MC-36 will also trigger the camera and allow him to program the shutter release and shutter release intervals.

His camera is a D300, and for most of his images he sets it for in-camera noise reduction. He will turn the noise reduction off, though, for star trail images that will be stacked in Photoshop. All his camera settings are manual, and he turns off autofocus. "With distant subjects I'll line up the infinity marker on the lens; for intermediate distance, I'll shine my headlamp light on my subject and focus manually."

The AF-S DX VR Zoom-NIKKOR 18-200mm f/3.5-5.6G IF-ED is pretty much his all-purpose lens. He also has an AF-S VR Zoom-NIKKOR 70-200mm f/2.8G IF-ED, an AF-S DX Zoom-NIKKOR 12-24mm f/4G IF-ED and an AF DX Fisheye-NIKKOR 10.5mm f/2.8G ED. "I try to keep the weight of the kit down because much of my night photography involves a lot of walking around city streets and mountain trails, but sometimes I'll carry two bodies—a D200 is my second camera. Because some of my exposures are so long, I can be shooting with the D200 while the D300 is taking an exposure."

His basic method is to first take a picture based on his best estimation and his experience, then check the histogram, then adjust the exposure according to what he's going after. "If the histogram shows the exposure smack in the middle of a bell curve for a 'correctly' exposed photo, a nighttime scene is likely to look like it was taken in the daytime. If you want it to look like night, you need to underexpose." Then it takes some work in post production for him to tease the image out of the file.

Obviously, the photographs Harold Davis creates don't come easy. His statement, "I'm aiming for the one great photo a week," gives you a clue to the time he spends shooting and processing. "It takes me a minimum of an hour to process a photo," he explains, "and a maximum of a couple of weeks, coming back to it again and again."

Then there's preparation and procedure. "When you're photographing at night you really have to be one with the camera and the equipment. I always wear a headband light, but it's a good idea to practice in the dark—put the camera on the tripod and make the settings."

When he's out shooting he's always aware of his situation and surroundings. "I'm an experienced outdoor photographer," he says, "and the night is not necessarily any scarier than the day, but at night I'm missing some of my senses. Hazards can be as simple as a pothole." He suggests that people starting out don’t go it alone. Around the block in your neighborhood, you'll probably be okay, but for something more ambitious—trail hiking or city exploration—take a spotter...or several. A good idea is a photo club or night photography group that might be in your area. In any case, let someone know where you're going; wear good hiking shoes; bring two light sources; and plan for the possibility that you might get stuck somewhere out in the wilderness. "I carry energy bars and extra clothing in my pack," Harold says. "A cell phone might not work in some areas, so I carry a device called the Spot Satellite GPS Messenger that can send a signal for help."

The rewards for all the preparation, shooting and careful processing are the startlingly beautiful images you can capture after dark. "There are as many photographs in the dark as there are in the daylight," Harold says. "Everything looks different, and that—along with unpredictable, unexpected results—is the attraction. There's also the chance to be a pioneer: daytime views are pretty well photographed, but at night things are different. Common objects look strange; even landmarks are brand new. There are beautiful compositions everywhere, and there's the interplay of different light sources and color temperatures."

For a photographer, the dark is more than just the absence of light.

Harold has detailed his night photography techniques and methods in his new book, Creative Night: Digital Photography Tips & Techniques. He is also the author of The Photoshop Darkroom: Creative Digital Post-Processing. You can see many more of his images and find out about his workshops at his website, www.photoblog2.com.