In the 1980s, a street photographer named George Forss was selling his black-and-white pictures of the Empire State Building and Central Park to tourists for $5 a pop. Like so many of New York’s sidewalk peddlers, he was just trying to make a buck. But his images stood apart from the typical fare.

As he saw it, New York was the Emerald City, and his cityscapes portrayed a luminous and majestic metropolis.

In framing the Brooklyn Bridge’s grandeur, he captured the masses who trudge across it daily. As fog crept over New York Harbor, he photographed the Statue of Liberty seemingly trying to peer through the mist, awaiting another ship of immigrants. And in what became his best-known picture, he snapped the Queen Elizabeth 2 gliding past the twin towers of the World Trade Center beneath a dark, ominous-looking sky.

He died at 80 on July 17 at his home in Cambridge, N.Y., in the foothills of the Adirondacks. His representative, Phyllis Wrynn, director of the Park Slope Gallery in Brooklyn, said the cause was heart failure.

To those who rushed past Mr. Forss on Midtown Manhattan sidewalks, he was just another street peddler. But that all changed in 1980, when the renowned photojournalist David Douglas Duncan encountered him near Grand Central Terminal and was riveted by his work. A former staff photographer for Life magazine, Mr. Duncan decided to use his influence to promote Mr. Forss.

Mr. Duncan published a photography book, “New York/New York: Masterworks of a Street Peddler,” through McGraw-Hill in 1984, and it made Mr. Forss a sensation. “Astonishment, disbelief, excitement, confusion and admiration held me captive while my eyes swept the vendor’s display of prints on a sidewalk,” Mr. Duncan, who died in 2018, wrote in the introduction.

The dust jacket carried praise from Henri Cartier-Bresson, Gordon Parks and Norman Mailer. Ansel Adams was taken by Mr. Forss’s high-contrast image of the Rocket Thrower sculpture in Flushing Meadows Corona Park. He wrote, “I have seen no photographs of recent years as strong and as perceptive.”

Reviewing a Forss show the next year at the New York Public Library in Midtown, Richard F. Shepard of The New York Times called Mr. Forss “a master of perceptions of the strength and beauty of the city in a way that few, if any, others have been able to achieve.”

He appeared on the “Today” show and was the subject of a BBC documentary. An exhibition of his pictures was held at the Brooklyn Museum, and the International Center of Photography in Manhattan acquired his work. Mr. Forss started charging $20 for his photos, and he gradually stopped hustling on sidewalks entirely.

“This is a whole new life for me,” he told The Times in 1985. “I was deteriorating on the streets.”

Much of the attention he received focused on the adversity of his life. Raised in orphanages, he grew up in the Bronx with polio, which made him reclusive as a child, and found escape when he discovered photography in his 20s.

After his career took off, things sometimes got weird in interviews when he spoke of his belief in an ancient race of aliens extraterrestrials who, as he told it, had telepathically communicated with him when he lived in the Bronx. He believed they had given him his creative talents and helped lift him out of hard times.

Mr. Forss purchased his first camera from a pawnshop on Eighth Avenue in Manhattan and later mastered the craft of building his own cameras from old parts. Working as a bike messenger, he trained his lens on New York as he pedaled across the city, and before long he started selling his prints.

With his modest profits he supported his invalid mother in the dilapidated frame house they shared in the Flatbush section of Brooklyn, where he had built a darkroom. An early portrait subject was his one-eyed cat, Bingo.

“Sure, I have a lot of resentment,” Mr. Forss said in an interview with Popular Photography magazine in 1984. “But it’s not going to show in my work. I want to be uplifted, and brought to the level of a beautiful place.”

His time in the spotlight would not last.

When he shot promotional images for Mercedes-Benz, his photos were deemed unusable, and he shrugged off the rejection. After a prospective client asked him to photograph a series of American cities, starting with Cleveland, he bombed in the interview and lost the job.

“What do you photograph in Cleveland, anyway?” he told The Times in 1984. “There’s no place like New York.”

George Forss was born on May 4, 1941, in the South Bronx. His father, Hank, was a street tough who was deported to Finland after George was born. His mother, Norma, was an amateur photographer who camped out around the city with a box camera and a flash gun to snap pictures of celebrities. Although details are scarce, city social workers had apparently removed George from his mother’s care.

After leaving the orphanage system in his late teens, George reunited with his mother, who suffered from crippling osteoporosis and rheumatoid arthritis. They bonded over their love of photography, and he became her caretaker.

In the late 1980s, as his rent in Brooklyn increased, an uncle left Mr. Forss a modest inheritance. He used it to buy a storefront building on Main Street in Cambridge, opening a gallery on its ground floor, where he sold his work and represented local artists. He lived with his mother and a half brother, Mickey, in Cambridge, where he became known as an eccentric figure. Occasionally a customer who noticed a black-and-white photograph of New York City in his gallery would ask him, “Is that a George Forss?”

He is survived by his half brother Mickey as well as another half brother, Donald, and his partner, Donna Wynbrandt.

As Mr. Forss settled into life upstate, his interest in extraterrestrial life was only heightened. In 2007 he self-published a book, “Enos,” in which he detailed his communications with aliens, and wrote of extraterrestrial experiences in a blog. He became an avid U.F.O. investigator who would drive across the region in a Volkswagen van checking out tips of sightings he had received.

When Mr. Forss searched the skies for alien life, he also trained his camera upward, hoping to photograph the beauty of something cosmic and incomprehensible.