"Photography is the study of light," I tell my students on the first day of class, as they open Basic Photographic Materials and Processes to chapter one, Light and Photometry. "Light is fundamental to photography. You will have become a photographer when you learn how light affects the scene before you."

I've been awake for hours, lying in bed, waiting for the dawn. In the night, I discern the darkness of the room not as blackness, but as subtle shades of grey: the soft grey of the comforter, the blackness of the bureau, the whiteness of Anne's face on the pillow next to me. This bed, which for so many years was filled with warmth, is cold. Anne is cold.

When I see long thin lines of white at the window, I grunt from the bed and pull the blinds. The morning light reveals a room not filled with grey, but with the muted pastels that Anne loved: the pinks and the blues and the greens. And on the bed lies Anne, who will not rise to greet this day. Her body, now so cold to the touch, has a soft, melted quality to it. Her mouth hangs open, a little crooked. We were married for fifty-eight years, and this is the image I'm left with: Anne, lying in bed, slack-jawed, white and cold.

I've photographed hundreds of bodies, some of them the bodies of friends. On assignment once in Belize, I was riding in a van full of journalists, when we were attacked by insurgents. They shot us. I was wounded, and badly, but had the presence of mind to photograph the bodies of my companions, my co-workers, my friends. This was work, and we had known the risks. I knew what I had to do, and I did it.

What do I do now?

I phone Louise. She is here within fifteen minutes. She doesn't ask to see her mother; this is no surprise. "I'm sorry, Pop," she says, and we hold each other. She comforts me, consoles me, makes me coffee. Louise is not so young herself. I sit at the kitchen table, warming my hands on the mug, watching her arrange the funeral. She's all business. She sits across from me with the phone, the yellow pages, a pad of paper, and a pen. She calls Anne's doctor, she calls the pastor, she calls the funeral home, and then, only then, she calls the rest of the family. "Mom's dead," she says. "She died last night."

I sit and drink my coffee, thinking of the night, trying to remember what it was like to lay there for hours next to my dead wife. I try not to fall to pieces.

The funeral is lovely. Anne was lovely. The pastor delivers a heart-felt message, drawing his text from Ecclesiastes: "To everything there is a season," he says, "and a time to every purpose under the heaven: a time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted." It's well-meant, but I cannot listen. Ecclesiastes is a young man's book. The pastor is thirty, maybe thirty-five. For him, it is a time to plant, a time to gather stones together. How blithe will he be about his time to die fifty years from now?

Louise drives me home after the internment. She makes chicken soup for lunch, and we eat it together at the kitchen table. She says that the best thing for me to do is to work. "Come on, Pop," she says. "Get out of the house. Go make some photographs."

She has good intentions, but my heart isn't in it. I've been making photographs for fifty years. They hang on the living room wall. I still see them in magazines, in newspapers, on the covers of books. After working as a staff photographer for the Oregon Journal, I spent nearly two decades working on assignment for National Geographic. When I was finished, I worked only for myself, making images to sell to the big stock agencies. I made the photographs that I wanted to make. That was before Corbis and Getty gobbled up all of the little players, cornered the market, making it nearly impossible to make a living at stock photography. For the past five years, I've survived mainly on royalties from old images.

I've made tens of thousands of photographs in my lifetime, and the last thing I want to do now is make more.

My students want tips, are always looking for magic bullets that will make their photographs better. There are no magic bullets. "One of the surest ways to improve your photographs," I tell them, "is to change your position. You spend your entire life looking at the world about 65 inches above the ground. What does the world look like at ten inches above the ground? At ten feet above the ground? Change your position and you'll change how you see the world. Your photographs can only be better for it."

I lie awake in bed, this bed that will never be warm again. Is this my bed? There's an emptiness here that is so foreign, so strange. Maybe I'm in the wrong bed. The wrong house. The wrong life. Where am I? Who am I?

After I retired from the Geographic, I began to teach photography courses at the community college. My students were a mixed bag: housewives, executives, kids with big dreams, all of them amateurs, making amateur photographs. I feel as if I'm looking at my life through the lens of an amateur photographer: I should study how the light affects the scene. I should change my position. I should get closer to my subject.

I should decide what my subject is.

When the first light comes, I get out of bed. I pull on some clothes, gather my equipment, and head to the hills.

Outside of Silverton, above Victor Point, I come upon a gravel lane falling into a dell and then rising again into the hills of fir and pine beyond.

I park the car and walk down into the lane, where I set up my tripod. I make four exposures. I'm threading a warming filter onto the lens when a green Toyota pickup turns into the lane. It's caked with mud. The white canopy looks brown. There's a CD antenna whipping in the wind, and a rifle mounted on the gun rack in back.

A burly Mexican fellow gets out of the truck. He lights a cigarette and saunters over to me.

"Hey," he says. "You shoulda been here yesterday. There was something like fifty elks out here yesterday." He takes a long drag on his cigarette, holds it. Exhales. The blue-white smoke pours from his lungs.

"I'm sorry I didn't ask first," I say, by reflex leading with an apology. Fifty years of photography, of trespassing for shots, have taught me that contrition is the better part of valor. "I didn't know who to ask. I didn't want to wake anyone."

"Shit," the man says. "I don't care. No problema." Drag, exhale. "My name's Diego," he says. I give him my name as we shake hands. Drag, exhale. "You shoulda seen it yesterday. Fifty elks, probably more."

He watches as I finish threading the filter. I frame another photograph. I bracket the exposure, then reframe and bracket again. I'm working as quickly as possible, uncomfortable with the audience.

"That's a nice one, he?" he says, pointing at my camera. I nod.

"Cost a lot of money?" he asks. Something in the tone of his voice makes me nervous. I calculate the odds: a two hundred twenty pound man in his prime against an one hundred fifty pound geezer with a bum knee. Not exactly in my favor. It's only a premonition, but when you're as old as I am, you put a lot of stock in your premonitions. I look to my car, which is parked a hundred yards up the lane.

"Cost a lot of money?" he asks again. "You a professional?"

"No," I say. "Yeah. I'm a professional. No, this camera didn't cost much. I don't believe in spending a lot of money for equipment. A person can make great photographs without spending a fortune for equipment."

What I've said is true and false. It's true that this camera has little real market value: it's a battered old Nikkormat FT-2, a fully manual camera that I've been using since 1973. But it's because I've used it so long that the camera has value to me. And the lens is certainly worth a whole lot of money.

Diego looks at me, looks at my camera. At last he says, "Drive up to the next gravel road and go to the end. There's a canyon back there. Great view. You can see the arroyo, the river, the back side of the park." He means Silver Creek Falls State Park.

"Great view," he says again. He throws his cigarette to the ground, climbs into the Toyota, and rolls down the window. "Adios," he says. "Good luck." He starts the engine and tips his cap. I watch as he drives down the gravel lane into the dell and then up the other side, into the hills.

Another piece of advice I give my students is this: "Be ready for anything. Keep your camera loaded with film at all times. You never know when an opportunity will present itself."

I make a dozen more photographs of the hills and the trees before I decide to take Diego's advice. I drive down the next gravel road and park at the end of the lane, at the head of an old logging road. I'm gathering my equipment when a black Chevy Suburban pulls up behind me.

A man climbs out. He's thin, clad in blue jeans, an Oregon State Beavers sweatshirt, and a cowboy hat. His tobacco's chewed, not smoked. He strides briskly, chest forward, spits at my feet. "Can I help you?" he says, but it's a challenge, not a question.

I appeal to him with my practiced contrition: spread my arms, open, expansive. I explain that a fellow in a green Toyota told me to come back here, told me I should take photos. "He told me there was a canyon or something."

"Well, shit," the man says, "that guy in the green Toyota, he don't own my land, now does he?"

I grant this to be true. There's an uncomfortable silence. Again I feel too old. I feel threatened. "I'm sorry," I say. "I'm a photographer. I'm just looking for something nice to shoot. I'll leave." As I speak, I begin to pack my equipment. It feels as if I'm packing my life, giving up.

Something about the situation causes the man to change his mind. He holds up a hand to stop me. He smiles. "I'm Derek Tolman," he says, and he shakes my hand. "This is my land. You can take all the pictures you want." He pronounces it "pitchers". "Just ask first, that's all."

"I appreciate it," I tell him, smiling my warmest smile. I really do feel thankful. "If I get anything good, I'll send you a copy."

This pleases him. He tells me that I should follow the old logging road back into the canyon. "The old homestead place is back there, and the mill, about a mile down the trail. You oughtta take pitchers of that. You wanna be careful, though. Watch out for bear. A sow and her three cubs passed through here at the end of the summer. Cats, too: cougars and the like. I ain't seen cougar lately, but they're around. And coyotes."

Permission to photograph the canyon doesn't seem like much of a gift anymore. I don't know much about bears and cats and coyotes, but I know enouogh to be scared to face them alone. I don't want to learn more. Still, I've been through worse, and I figure the likelihood of encountering any wildlife is slim.

"Good luck," says Tolman, and then he climbs back into the Suburban and drives away. I consider calling it a day, driving home. The clouds have begun to part, and there is the promise of sun. I'm cold, and the idea hiking a mile through the tall grass is unappealing. My knee has been sore all morning. Still, the photograph possibilities inherent in an old mill spur me on. I'd like to see this homestead place.

Every beginning photographer has the same problem: he does not fill the frame with his subject. He stands back, and thinks that he his taking a photograph of his wife. He's not taking a photograph of his wife. He's taking a photograph of the driveway, the garage, the sidewalk. His wife happens to be in the photograph, but the photographer has not made her the subject.

"Get closer," I tell my students. "Get closer."

The logging road drops and then begins to rise. As it does, I find myself above the tops of the trees on the hillside. Soon I have a view to the other side of the canyon. I reach a broad, flat grassy clearing where I pause to rest. I sit on a large rock and rub my aching knee. The hillside falls away steeply here, and fewer trees grow on its side. I can see the entire canyon. I can hear the faint rushing of the river.

Opposite my vantage, maybe a mile away, another hill, one of a series, rises, cloaked by an unbroken forest of evergreens. Below, a narrow river -- a stream, really -- courses through the valley. A mill stands beside the stream. There is a house nearby, and a barn: the old homestead place. A bridge spans the stream. It's a lovely vista, not breathtaking perhaps, but there are plenty of photographs to be made here.

"If I were one of my students," I think to myself, "I'd be content with taking a photograph from here. I'd take a photograph of the mill from here, but all I'd have is an image of trees."

I'm looking for a way down into the valley when I hear a noise behind me.

"Hey!" a voice calls. It echoes in the valley below: "Hey! Hey! Hey!"

I look up to see Diego standing on the edge of a bluff. He waves at me with his left hand, which is holding a cigarette. His other hand is holding his rifle. "Buena vista," he says.

"You seen any bear?" he asks. "There's bear around here. You should carry a gun to be safe."

I feel less safe with Diego carrying a gun.

"Stay there," he says. He puts the cigarette in his mouth and disappears from view.

As I wait for Diego to join me, I explore the clearing. I'm not sure what I'm looking for, but I soon find it anyhow. There's a little-used trail running from the bluff to the valley floor. It's a steep run -- several hundred feet in a quarter mile -- and although my knee is sore, I start down the trail. I lose my balance midway down and fall to the ground, sliding through the tall grass. I lay still for a moment, perform a mental inventory of my body. Broken hip? Broken collarbone? Twisted knee? Everything seems fine.

I scramble to the bottom of the slope, to the edge of the grassy field. The rush of the stream is loud here. I look back up the slope and my heart sinks; the descent was difficult, but it would be impossible for me climb. I can't go back the way I came, so I decide to walk to the river, to cross it, to photograph the mill and homestead, which was my original objective in the first place. If Diego finds me, fine. If not, fine.

I track through the long wet grass toward the river, toward the mill. My pants and shoes become soaked. I hate the feeling of wet feet, and now my entire lower body is wet. I'm cold and miserable, and I'm beginning to feel edgy. The bridge doesn't inspire confidence. It comprises several rotting planks tenuously fastened with rusted nails. It's older than it is strong. When I step on it, the entire structure sways ominously, but what have I to lose? I hobble across.

The mill is a wooden thing, similar in construction to the bridge, and in a similar state of repair. If I touched it, it might collapse. It looms large, and the horizontal rays of the morning sun cast crisp shadows, creating sharp definition along the edges of boards and windows. I limp around the mill, skirting the edge of the stream, searching for a photograph. I find one at the corner of the mill: with a wide-angle lens, with side-lighting, with the richly textured green hillside of trees in the background, this shot has promise. It is, perhaps, an image I could sell.

I erect the tripod, mount the camera, mount a 20mm lens. I consider my options. Do I need a polarizer? A warming filter? Fill flash?

Then Diego is by my side, big and wet and steaming. He's angry. "Where did you go, vato? What are you doing here?" he asks gesturing toward the mill with his rifle.

"I'm going to photograph the mill," I say. I'm tired of this whole thing.

"You shouldn't be here," he says. "Muy peligroso. It's dangerous."

"I'll be careful," I say, and I turn to my camera. I look through the viewfinder and frame the shot. It's perfect. I make the photograph.

As the shutter clicks, Diego shouts, "Hey!" I look up to see that he has raised his gun, and has pointed it toward me. He's staring down the barrel of the rifle.

So this is it, I think, and I do not even move. The air explodes with his shot, but I feel nothing. I am not shot. I hear a crash and then a thrashing in the long grass. Diego drops his rifle, and runs toward a mass of black fur in the grass. "El oso," he says, and it sounds as if he is sobbing. He drops to where the bear is lying in the grass, writhing, bleeding red, becoming still. It's a small thing, just a cub, and in a shortly it is dead. Diego is beside it, stroking it, sobbing.

"A bear," he says. "A little one, small but hungry. Dangerous. He's been living here for three months."

He sits back, slumping into the long grass. He pulls out a cigarette and lights it, then looks me in the eyes and tells me, "I came to see him every day. He was hungry, and alone. Sometimes I brought food."

Drag. Exhale. He says, very deliberately, "You should be more careful."

What I want to say is that I'm old, and what have I to lose? I want to say that I've had a long life. I had fifty-eight years with a woman I loved. I've spent my time with work I enjoy, making photographs, changing my position, getting closer. This is the truth. I want to ask Diego, "What am I now? An old man with a bad knee and a camera. Why should I be careful?" What I actually say is: "I'm hurt. I'm lost." This is the truth, too.

Diego smiles and pats the bear. "I know," he says. "I'll show you the way out."

Magic bullets. Everyone wants magic bullets. I only know of one. "The best way to improve your photography," I tell my classes every single week, "is to make more photographs. Get outside. Work. Make some photographs. Only by learning what doesn't work can you learn what does work."