After an early morning drizzle, the tiny blueberry clusters manage to shine a bit despite the overcast sky. With my tripod-mounted camera just an inch or two from the dangling new growth, I look through the viewfinder and focus close, very close. I push the tripod nearer yet and adjust the lens until only the baby blueberries fill the frame.

The wind sends shivers through the miniature scene I am trying to compose. Even slight movement makes it difficult to set the proper exposure, so I stick my hand in front of my lens and meter the light reflecting off my skin. Hmm. I open up one f-stop, sit back and press the cable release. The shutter opens and, a half-second later, closes. I have my shot. I hope. With nature photography, you never know until you see the picture.

For a moment, I consider shooting a few more frames at different exposures just to be sure I get at least one right, a technique known as bracketing. But my guru is nearby, and he doesn't bracket.

"I don't believe in it," photographer Bill Lane had declared during our briefing the night before. "I think you should learn to get the exposure you want in one shot because sometimes you only get one chance at that shot."

We were in a conference room with a gorgeous view of the Potomac River slipping from sight as night fell. Twelve of us sat around a table strewn with camera gear, photo books, magazines and catalogues. For a few Friday hours, Bill lectured us on the basics of nature photography, illustrating the complexities of exposure, composition and technique with his own slides of bald eagles and fox pups. He was preparing us for 11/2 days of shooting in and near Virginia's Westmoreland State Park, about 90 miles south of Washington.

"If you aren't sure what you are doing, stand right next to me and watch what I do," Bill tells us. "Otherwise, you're free to go off on your own." He runs his workshops loosely -- this is as much vacation as it is classroom, a chance to wander outdoors, talk shop and share equipment with fellow photo hobbyists. Yet Bill does have one rule for which he allows no exceptions: Everyone must switch their cameras to manual mode. "In this class, automatic is a dirty word," he says.

For the past nine years, Bill and his wife, Linda, have run Nature's Image Photo Workshops. Their sessions, one of several photo workshops in the area, run each spring and fall mostly in state parks in Virginia, West Virginia and Maryland. The outing before this one found them farther away, in Tennessee's Great Smoky Mountains. Up next, in October, is Hungry Mother State Park in Marion, Va.

Westmoreland in the spring, when the pink lady-slippers and other flowers are beginning to bloom, is a favorite site of the Lanes. They also like it for the Potomac River Retreat House, where we divide up the several bedrooms between us. Unlike some of their workshop locations, which don't offer nearby accommodations, here you can wake, walk out the door and start to shoot. And the shooting starts at sunrise.

After the brutal 5:15 a.m. wake-up call, two cups of coffee from the near-industrial-size percolator and a breakfast of peach yogurt, granola and banana, I review my notes on how to shoot a sunrise: Meter on the brightest spot, then open up one stop. When the misty rain lets up, I go out to find dawn and some blueberries.

The park in early spring wears several shades of green offset by a few white- and purple-blossoming dogwoods. Fifty yards from the road and almost hidden by new vegetation, Mike Spencer of Fairfax kneels in front of a patch of electric-green moss and trains his tripod-mounted digital Nikon D100 on it. At the park's entrance, a quarter-mile away, Charles White of Temple Hills, Md., focuses on a patch of red columbines and snaps a few Jpegs.

The group is evenly divided between film and digital cameras. Harlow Frietag of Arlington, devoted to film, says he has only one use for the new technology: "I use a digital to take pictures of my car in a parking lot so when I come back I can find it."

After the blueberries, my search for subjects is unsuccessful, so I simply enjoy the walk in the park. The clock ticks closer to lunchtime, and I find a few others in the group lingering near the dogwood opposite our parked cars. No one exclaims over what they found, but neither are they disappointed. Getting their eyes adjusted to their viewfinders was a good warm-up.

By 11:30, we're back at the retreat. Linda has covered the table with bowls of tarragon chicken, wheat-berry Waldorf salad and several other homemade dishes. Tortilla soup simmers on the stove. For dessert, chocolate mint cake. For a while, no one talks photography.

Bill, who'd skipped lunch to find a pink lady-slipper in bloom for us to photograph, reappears a few minutes before we depart. We are off to Caledon Natural Area, about 30 minutes away, where we will see plenty of jack-in-the-pulpits.

All of the workshops specialize in nature photography, and ours emphasizes close-up shots. But what Bill really wants us to learn is how to work with light. "Exposure is the biggest stumbling block," he says.

A camera's built-in meter, which measures light and recommends exposure settings, is invaluable but not infallible; some situations require the photographer to depart from what the meter says. "Trying to figure out tones and correcting is one of the hardest things in photography," he says.

Off to one side of the Fern Hollow Trail, Ken McCoy is setting up his Hasselblad, a professional medium-format camera that produces beautifully detailed square negatives. Ken retired as the director of the nuclear medicine lab at Washington's Providence Hospital in 1977 and has been shooting pictures as a serious hobby ever since. At the moment, he is focusing on a jack-in-the-pulpit, a green flower with a large, arched petal that hangs over the taproot, or corm, in its center.

Later, back at the lodge, the picture I want is waiting for me. Actually, it is the picture everyone wants. Nested atop a gazebo 100 yards or so from the Potomac shore, an osprey has settled down in the golden light of early evening. It sits there patiently as we set up our tripods.

Neither of my lenses can get me anywhere near the osprey, and I am about to give up. It's dinnertime and my stomach is steering me back to the house and to Linda's spaghetti. But Bill arrives outfitted with a colossal 600mm lens. Through it, the osprey and nest nearly fill the frame. His big lens fits my Nikon, so he snaps it on and I compose a shot, considering the light on the nest. Bill has three questions he wants us to ask about light : What tone is it? What tone does the camera think it is? What tone do you want it to be?

I set my exposure the way he taught us, adding just a little more light than the meter suggests to pick up the bright highlights on the osprey's feathers. I click the shutter.

"Can I bracket?" I ask him, worried I've done something wrong and wanting another shot, just to be sure.

Bill just looks at me and lets me decide. With a little regret at my lack of confidence, I make a quick adjustment, cross the fingers on my free hand and snap the last frame on the roll. I'll find out how much I've learned -- when I get my slides back.

Got it: The author shot this picture of an osprey nest at the end of his nature photography weekend in Virginia's Westmoreland State Park. (Photo Matt Mcmillen)