Lynn Geesaman photographed the gardens of France, the parks of England, the canals of Belgium.

But her favorite location was the darkroom of her Edina home.

There, she gave her measured, formal landscapes an ethereal, soft-focus feel. Her black-and-white photographs look like etchings, her color photographs like watercolors. Those works wound up in homes and museums across the country, from the Whitney Museum in New York to the Walker Art Center in Minneapolis.

“Lynn produced an extensive body of work of distinctive images that were immensely appealing to people,” said Yancey Richardson, her New York gallerist. “She had a terrific eye for formal composition, and then she used this very unique approach to make these beautiful prints that were atmospheric, poetic and magical.”

Geesaman, a self-taught, internationally known artist, died Feb. 29 after living for 15 years with dementia. She was 81.

After growing up in suburban Cleveland, Geesaman graduated from Wellesley College in 1960 with a degree in mathematics and physics. She was working as an experimental physicist at a radiation laboratory when she met her husband of 57 years, Don Geesaman. “We met, strangely enough, at a nuclear weapons lab,” he said, “which is not thought of as being the best place to meet a spouse.”

After marrying and moving to Minnesota, she taught middle school math and raised two daughters. Then a relative introduced her to photography — to the darkroom. “I remember so vividly the day he showed me how to do test strips in the darkroom,” she once said. “I had never seen or imagined you could make pictures like that and I thought it was wonderful.”

She began taking photos as part of a camera club. “What’s so magical about my mom’s career is that it evolved so authentically,” said Sarah Grubert, her daughter. “No art school, no shtick.”

An identical twin, she first photographed other twins. But landscapes became her focus. In the early 1980s, she shot at Minneapolis quarries and gravel pits, playing with scale. In the resulting sepia, 4-by-4-inch images, small mounds “looked sort of enormous, like part of the landscape rather than an excavation site. … They felt monumental,” said Thom Barry, Geesaman’s longtime dealer.

She began photographing formal gardens almost by accident, according to a 1995 Star Tribune story. With a McKnight Foundation grant, she headed to Louisiana to shoot oil refineries. But on her day off, she visited an antebellum garden. She shot her square-format works with a Hasselblad, spying lines and shapes through its foot-long black tube. Trimmed topiary. Straight-edged hedges.

Geesaman became known for her “elegant black-and-white images, taken in fog or diffuse light, that underscore the formal geometry of her scenes,” Star Tribune critic Mary Abbe wrote in 1999.

Each morning, clad in a bathrobe, she’d pad down to her makeshift darkroom — a little basement kitchen with black vinyl curtains she sewed to keep the light out. It was there that her photographs became “dreamlike and spectacular,” Barry said, thanks to a secret diffusion technique that softened an image without taking it out of focus.

“The darkroom is where I shape the image to my ideals,” Geesaman once said. “If I am able to work any magic, most of it occurs in the darkroom.”

With their soft focus, her landscapes evoke the early Pictorialist photographers, said Christian Peterson, former associate photo curator at the Minneapolis Institute of Arts. “She and I shared an affinity for that aesthetic,” he said, though it wasn’t in fashion at that time. “She was a bit of an outlier.”

Geesaman’s survivors also include her twin sister, Leslie Zedd, and daughter Rachel Cleveland.