Raymond Goodman had been pondering the idea of creating a series of portraits of people involved in the local sustainable farming movement for some time, but he was at a loss for a unifying visual theme, some element that would tie the series together.

Then he looked down at the ground beneath his feet.

Goodman, a photographer and beekeeper who lives in Raleigh, was visiting a friend, Matthew Cronheim, a farmer at Commonplace Farm in Durham County.

"I was taking some pictures in the field at Commonplace," Goodman said. "They mulch the paths between the rows with old coffee bean bags. I took a picture looking down the path of Matthew's feet, with these walls of tomato plants on either side and that burlap underneath, and it just occurred to me.

"I knelt down and picked up some of the burlap and looked through it, and I thought, 'Ah-ha, this might work.'"

The result is "Burlap: Portraits of Piedmont Farmers," an exhibition of large-scale photographs on display at the Bull City Arts Collaborative at 401 Foster St. and at the Piedmont Restaurant two doors down.

The series, Goodman says, is an attempt to capture "the faces of the clean food movement in our region." His subjects, many of whom are relatively young, have come to farming via many paths, but they all embrace the concept of small-scale, locally-focused sustainable agriculture, a fast-growing niche that is complementing, and to some extent supplanting, the long-dominant model of large-scale industrial farming

"People think of farmers and they tend to imagine crusty old men with weather-beaten faces," Goodman said. "And that's true, but there a whole lot of other faces, too."

Each photograph in the exhibit is a full-length color portrait of the subject (or, in a few cases, subjects), taken outside in their fields or farms, standing in front of a curtain of burlap. The subjects in the foreground are in crystal focus; the semi-transparent burlap behind them veils the farmland, foliage and sky beyond, lending it all a diffuse, subtle shading.

"I like the way you can see the changing seasons in the colors in the background," Goodman said. "And you see how much the light changes, how many different blues the sky can be. Some of the shots were taken in the same space, just minutes apart, but they're utterly different."

The burlap fabric itself adds a grainy, textural quality to everything behind the subject.

"It all looks a little surreal," said Dave Wofford, who runs Horse and Buggy Press, which shares the space, and curated the show. "You have that sharply focused foreground and soft, dreamy background. It's a great contrast."

For the display Wofford puts in the gallery window, he chose a portrait of Tim and Helga McAller of Four Leaf Farm in Orange County. Tim, wearing a blue T-shirt with a brilliant red graphic of a tomato on the front ("I think I'm wearing the same shirt right now, actually," Goodman said, unzipping his jacket to confirm it.), stands with his arm around Helga, who wears crimson overalls and a daffodil-colored shirt, whose hue is echoed by a flowering cover crop in the background.

"They look so exuberant, I put them in the window," Wofford said. "In the morning, when the sun shines on the front window, it's like they jump out and say hi to people walking by."

Goodman has been interested in farming since he was child, when he would visit his mother's family in Germany, where they raised pigs and sugar beets. He has gotten increasingly involved as the years have gone on.

"When my daughter was born, that really got me thinking about the food we eat, where it comes from, our impact on the earth, the legacy we leave," he said. "I started going to Carolina Farm Stewardship Association conferences, and I decided I wanted to explore sustainable agriculture in more depth."

Hence the bees.

"I wanted to raise livestock, but the chickens fell through," he said. "So I thought, well, bees are livestock, right? I got some hives last April. It's definitely a learning experience; if you don't do it right, the bees will let you know."

His first subject for the "Burlap" series was Sean Barker, who runs Part and Parcel Farm, growing crops he sells to an expanding list of clients in what used to be his front yard just outside Raleigh.

"I feel a little funny even being referred to as a farmer," he said. "I grow things in my front yard - am I really a farmer? But what we've learned is that if you cultivate and manage properly, you can turn out an amazing amount of food and feed a lot of people in a really small space. One of the basic questions the sustainable agriculture movement asks is, 'Do you have to have hundreds of acres to be a farmer?' And the answer is no."

Goodman and Barker spent the better part of a full day working on that first photo shoot. In addition to the changing light, getting the burlap to cooperate was the most difficult challenges, Goodman said. He hung the fabric from a curtain road suspended atop a pair of stands, and trying to get it to hang flat, without wrinkles, was tough, especially in the wind.

"It wants to be a sail," Goodman said. "If the breeze even thought about blowing, that stuff would billow up and try to take off. It may look like it's just hanging there, but there's a lot more to it than that."

He gave his subjects no instructions about what to wear, and in most cases discouraged the use of props like tools or watering cans. There are a couple of exceptions.

"I was shooting Ben Berry and Kathleen Smith of Maple Spring Garden in Orange County, and Ben said, 'Can I go get a chicken?'" Goodman said. "So he got a chicken, and I said, 'If Ben's holding a chicken, Kathleen, maybe you should have something, too.' She said, 'I'll go get a pumpkin!'"

His subjects also include a group of Karen refugees from Burma who farm with the Refugee Agricultural Partnership Project of Carrboro.

The commitment to local sustainable agriculture that Goodman's subjects and exhibition embrace is a not a new idea, he said, but more like a return to the small-scale family farming that once fed the nation.

"The 'Get big or get out' approach post-World War II is what led to the Monsantos of the world," he said. "This is a reaction to that. You've heard 'Think globally, act locally'? These people are doing it."