Rust never sleeps. Neither, it seems, does Jonas Mekas. The filmmaker, an icon to free thinking cineastes worldwide, rarely slows down until the sun comes up.

“I am a night worker,” he says by phone one recent morning, sparing a few minutes before heading out the door of his Greenpoint, Brooklyn, apartment. A strong Lithuanian accent lends his words a hearty flush of old-school immigrant vigor. “When the city sleeps. When the air is clear. When all the business-making is clear from the air. This is when I edit!”

At 83, Mr. Mekas is as busy as he’s ever been in the nearly half-century since he arrived in New York. Along with his brother, fellow filmmaker Adolfus, he escaped from a Nazi labor camp in 1945, then spent four years in several displaced persons camps in Belgium before landing in Williamsburg, Brooklyn. It wasn’t long before Mr. Mekas picked up his first movie camera. His landmark film “Lost, Lost, Lost,” like most of his work a diaristic collage, begins here. Shot between 1949 and 1963, the film chronicled his migration and the travails he experienced in the immigrant community. For his most recent piece, the 80-minute video “A Letter from Greenpoint” (2004), the filmmaker returned to live in Brooklyn after selling his SoHo loft of 30 years.

“A Letter From Greenpoint,” which screens tonight at the Museum of the Moving Image in Astoria, is scarcely an autumnal work. This might seem strange, since it was shot near the snowy end of 2004, as Mr. Mekas quit his overstuffed Broadway home for that most Eastern European of Brooklyn neighborhoods, where the predominant language is Polish. Instead, it crackles. Shambling and poetic, the camera tracks Mr. Mekas’s steps into his new life: singing along to the radio — Bob Dylan’s “Like a Rolling Stone,” no less — or killing off a bottle of wine in his new (and similarly cluttered) abode; teasing a young sidekick (the actor Ben Northover) who gushes obsessively over the singer Norah Jones; chatting up the hipsters and old-timers alike who flock to the local taverns; capturing street scenes at skewed angles that always catapult the viewer into the next episode.

“I have a new set of friends and bars,” says Mr. Mekas, who dons his black fedora and takes a short walk late each evening to Pete’s Candy Store, a longtime hangout for the neighborhood’s many artists and musicians. “It’s really exciting. I prefer young people. I like that energy. It’s amazing how fast people can get stagnant and old.They reach 35 and 40 and I don’t want to see them.”

Mekas speaks as a man who is uncomfortable with too much comfort. Perhaps the single living New Yorker most closely associated with 16mm celluloid — he is the founder of the legendary Filmmaker’s Cooperative, and, heroically, secured his 35-year-old Anthology Film Archives a stable home on Second Avenue — Mr. Mekas set it aside 15 years ago because he felt he was repeating himself.

Though he’s been shooting video ever since, Mr. Mekas claims that “A Letter From Greenpoint” is the first time he felt completely at home in the medium.

“I think now I am very free,” he said. “I am as free with video as I was with the Bolex. I thought video would be simple, but it took a long time to get used to it. Now I shoot with myself and others and nobody gives a damn. I act spontaneously. I just become the camera and shoot.”

Back in 1975, Mr. Mekas offered a concise description of his approach, writing in the program notes to his 1968 film “Diaries, Notes, and Sketches (Walden)”: “Either you get it now, or you don’t get it at all.” It continues to serve him.

“I shoot in little spurts,” he says now. “One, two, three minutes. Little poems or haikus.”

Rather than dating him as some lingering 1960s holdout, his concept is as one with the 21st century zeitgeist. Apple has hired him to produce 365 short videos for its next-generation video iPod, expected to go on sale later this year.

“I’m embracing the new technology,” he says, having already shot about 80 of the 3-to-5 minute clips. “Life and art and cinema keeps moving ahead. There’s no use in holding onto something that’s already past. I am here and now!”

Besides his own project, Mr. Mekas will curate short works from the likes of Martin Scorsese — also the subject of a forthcoming documentary — Jim Jarmusch, and other filmmakers, including his frequent collaborator, the French director and dancer Virginie Marchand. He’s also looking forward to culling the Anthology’s vaults for classic avant-garde cinema that can translate to the new format: an “iPod Pantheon”he calls it. Of course, there’s also “Dancing With Fred Astaire,” his collection of anecdotes, which will soon be published in France. And the documentary on Kazuo Ono, the great 100-year-old Japanese butoh dancer, on which he ran camera for Ms. Marchand. Also, the exhibit at the Maya Stendhal Gallery, coming in November.

Fans can hear all about it tonight in Astoria, where Mr. Mekas will be feted at a pre-screening reception. And if the musical selections heard in “Letter From Greenpoint” whet the ears for more, they can witness Mr. Mekas sing on Saturday. He’ll join the Here and Now Orkestra for a 10 p.m. set at the Stone, the Avenue C new music venue overseen by the filmmaker’s friend, the composer John Zorn.

What’s on tap? For once, the loquacious Mr. Mekas turns slippery. “I’m not going to reveal,” he says coyly. “I like to improvise.”