By JULIE SCELFO


The ability to observe the private lives of strangers from the windows of our homes - and the knowledge that they can often watch us, as well - has long been a staple of city life. It has provided material for countless movies and books, most recently “The City Out My Window: 63 Views on New York,” a book of drawings by Matteo Pericoli that asks well-known New Yorkers to describe what they see from their windows, and is the subject of “Out My Window NYC,” a new series of photographs by Gail Albert Halaban.

“In a large city where there’s a lot going on around you, it can feel very isolating and lonely,” Ms. Halaban said. “By having contact with these total strangers through the window, it’s a safe way of having a relationship without the hard part of a relationship.”

It’s a more intimate version of what the pioneering urban renewalist Jane Jacobs called the ballet of sidewalk life, said Calvin Morrill, a sociologist at the University of California, Berkeley.

“Simply looking out your apartment window and seeing other humans doing an activity in a consistent way and at a similar time can provide stability and support,” Dr. Morrill said.

Moreover, in an age of reality TV, watching the neighbors can seem just like watching television.

Kerry Gaertner, 30, who lives in Cobble Hill, Brooklyn, was watching “The Real Housewives of New York City” when she realized that one of the stars, Alex McCord, lived directly across the street. Fascinated, she began making mental notes every time she saw Ms. McCord and her husband coming or going.

Although their relationship consists mainly of “nodding hello in the morning,” she said, she now feels obliged to act as their defender, making sure acquaintances know that she seriously doubts their on-screen portrayal as “social climbers.”

“They’re perfectly nice,” she said. “If they weren’t on television, they would be totally unremarkable neighbors. And I mean that in the nicest way possible.”

Mark Morris, the choreographer and dancer, whose view is included in “The City Out My Window,” said he regards the building across from his home on Third Avenue in Manhattan, where people are constantly moving in and out, as something of a cineplex. “There’s an empty apartment, and I see the new people, some couple, come in,” Mr. Morris, 53, said. “Then they cover the windows. Then you can’t tell from across the street if they’re male or female - and they’re naked, which is always interesting. Then a few weeks later, it’s empty again.”

To satisfy his curiosity, Mr. Morris said he keeps a set of binoculars handy, and isn’t bothered if the neighbors watch him in return. “It’s kind of comforting,” he said. “Everyone is alone together in their own separate units, but everybody knows how together they are. I don’t think it’s creepy. It’s kind of nice. That’s why you live in a big city.”

Some people claim to observe an unwritten code of looking away when they inadvertently observe something too private.

Lisa Rubisch, 39, a commercial director, describes herself as “nearly obsessed with watching people,” but said she still makes a point of avoiding the windows directly across from her apartment near the Bowery, where the blinds are always open. The woman who lives there often wears nothing but underwear, Ms. Rubisch said, “so I try not to look. And the way the street is, we’re very close. You can really see every detail in the room.”

Those who don’t mind watching and being watched, though, sometimes find that good things can come of it.

Debrah Pearson Feinn, 62, a painter, noticed another painter across the street observing her at work. Their anonymous relationship continued for several months, she said, until finally he “called me and said ‘Hi, I wanted to introduce myself.’”

“We literally started a friendship,” she continued, “and he came over and had dinner with me and my husband.”

More than 30 years later, they’re still friends.

PHOTOGRAPHS BY MICHAEL APPLETON FOR THE NEW YORK TIMES; BELOW, TODD HEISLER/THE NEW YORK TIMES

Clockwise from left: Debrah Pearson Feinn befriended a painter she observed through her window; Lisa Rubisch spies with discretion, and Mark Morris says he doesn’t mind if the neighbors watch him, too.