She roamed the streets of New York, camera in hand, finding opportunity at every corner. An obituary by William Grimes for the New York Times.

Arlene Gottfried, whose arresting images of ordinary people in New York’s humbler neighborhoods earned her belated recognition as one of the finest street photographers of her generation, died on Tuesday at her home in Manhattan. She was 66.

Her brother, the comedian and actor Gilbert Gottfried, said the cause was complications of breast cancer.

Ms. Gottfried roamed the streets of New York, camera in hand, finding opportunity at every corner. Much of her work recorded the daily routines and local characters in the city’s Puerto Rican areas, where cultural exuberance coexisted with poverty and urban blight.

In one of her most celebrated images, a nun leads a group of Roman Catholic schoolgirls in Communion dresses down a trash-strewn street lined with old cars, one of them with a plugged-in television set on the hood tuned to a western.

She photographed a gospel choir in Harlem; followed a club dancer and former convict known as Midnight as he declined into mental illness, a journey recorded in her book “Midnight” (2003); and turned her lens on her own family in her mother’s final years for the photo essay “Mommie,” published last year.

She struck pay dirt on a nude beach in Jacob Riis Park in 1980, when a Hasidic Jew, dressed in black hat and overcoat on a scorching summer day, unexpectedly appeared. A nude bodybuilder approached and asked her to take a picture of the two together “because,” he said, “I’m Jewish.” She obliged. The unforgettable photo shows a flexing nude, smiling proudly, next to his thoroughly nonplused and emphatically clothed companion.

Ms. Gottfried’s subjects were never specimens, held up for cold examination. She was part documentarian, part social worker, a warm and sometimes lingering presence in the lives she recorded. She spent 20 years with Midnight and ended up joining the gospel choir that was the subject of her first book, “The Eternal Light,” published in 1999.

“How her eye captures people, and how she touches them, that’s hard to explain,” her brother told The Guardian in 2014. “Someone else couldn’t see the funny or odd or touching thing, and capture it. Kind of like how a singer can have a great song, but not know how to sing it. She’s able to do that.”

Ms. Gottfried is prominently featured in a documentary film about her brother, “Gilbert,” scheduled to open in November.

Arlene Harriet Gottfried was born on Aug. 26, 1950, in Brooklyn. She spent her early childhood in Coney Island, living above the hardware store that her father, Max, ran with his brother, Seymour. Her mother, the former Lillian Zimmerman, was a homemaker.

When Arlene was 9 the family moved to Crown Heights, whose growing Puerto Rican population captured her imagination. In later years she took the cry of a Puerto Rican street vendor, selling cod fritters and fireworks on the Fourth of July, as the title of her book “Bacalaitos & Fireworks” (2011), an unvarnished but loving look at Puerto Rican life on the Lower East Side and in Spanish Harlem.

“It was a mixture of excitement, devastation and drug use,” she told The New York Times in 2016, describing the scenes she recorded. “But there was more than just that. It was the people, the humanity of the situation. You had very good people there trying to make it.”

When she was in her teens, her father gave her an old camera, and she began taking pictures as she walked around the neighborhood, a habit that became a career. “We lived in Coney Island, and that was always an exposure to all kinds of people, so I never had trouble walking up to people and asking them to take their picture,” she told The Guardian.

Ms. Gottfried took photography courses at the Fashion Institute of Technology in Manhattan because, she once explained, she did not want to listen to lectures or do homework. After leaving the school, she found work doing commercial photography at an advertising agency.

In the mid-1970s she began a freelance career in which her work sporadically appeared in The New York Times, The Village Voice, Fortune and Life.

She discovered a second life as a gospel singer in the 1990s. Selwyn Rawls, the director of the Eternal Light Community Singers in Harlem, invited her to join the choir. Belting out songs of praise, she began appearing with choirs at gospel festivals and eventually emerged as a soloist. Most recently, she sang with the Jerriese Johnson Gospel Choir.

In addition to her brother, she is survived by a sister, Karen Gottfried.

Although well known to photographers and photo editors, Ms. Gottfried remained unknown to the larger public for most of her career. That changed when her black-and-white work from the 1970s and ’80s, some of it collected in her book “Sometimes Overwhelming” (2008), caught the wave of interest in the gritty, dangerous New York of yesteryear. An exhibition at Daniel Cooney Fine Art in 2014 attracted the attention of the national news media and led to shows in France and Germany.

The attention seemed to startle her, since she described her vocation in modest terms. “I think I wander around and I see things that just speak to me, in one way or another,” she told Time magazine in 2011. “There are things that you try to say something about, or a moment you want to hold.”