Whitney Sudler-Smith was too young to be a part of the raucous party scene that was 1970s New York. So the 41-year-old screenwriter and son of the socialite Patricia Altschul did the next best thing: he made a movie about it.

Or, more accurately, he made a movie about one of the era’s most emblematic figures: Halston.

The documentary “Ultrasuede: In Search of Halston” focuses on the life and times of Roy Halston Frowick, the Iowa-born designer who as a milliner in Chicago in the 1950s made hats for movies stars. Later, as confidant to celebrities like Elizabeth Taylor and Liza Minnelli, Halston became a star in his own right, the epitome of New York disco-era glamour. The film touches on the designer’s drug use and his business misfortunes. He lost control of the Halston name in the 1980s, and died of complications from AIDS in 1990.

“As a child of the ‘70s, whose tastes were formed during that time, I think Halston represented everything that was right and was wrong with that time,” Mr. Sudler-Smith said a week before the film’s premiere on April 30 at New York’s Tribeca Film Festival

The film started as a portrait of “great eras of decadence - Berlin in the ‘30s, Paris in the ‘20s and New York in the ‘70s, with Halston as a figurehead,” he said. Ultimately he decided that Halston deserved his own movie. “He really was a great artist,” Mr. Sudler-Smith said.

But Halston was known as much for his jet-setting lifestyle as for his minimalist designs . He became a mass-market branding juggernaut, licensing things like cologne and carpets. At his apex, Halston reigned from a lobby-size New York office on the 22nd floor of the Olympic Tower above Fifth Avenue, where the mirrored doors alone cost $500,000, according to the movie.

Mr. Sudler-Smith relied on friends and family contacts to gain the trust of many of Halston’s friends, including Liza Minnelli. “I was terrified: my first interview, Liza Minnelli, in her apartment - Warhols of her, her mom and Vincente Minnelli” on the walls, he recalled. Working with the editor and producer Anne Goursaud and others, he spent four years on the $2.2 million movie. Much of the money came from investor friends and some credit cards.

After an interview, the director, still anxious, sat bolt upright. No wonder. The fashion world will soon scrutinize his debut effort, and so will many others. Vanity Fair was a host of the party after the New York premiere at Trump SoHo. For the Los Angeles premiere at the Los Angeles County Museum of Art on May 12, Elizabeth Taylor will serve on the host committee. He is now, it seems, part of the Halston legacy.

“It’s like I’m having my debutant’s ball, at 41,” he said.


By ALEX WILLIAMS


EVAN SUNG FOR THE NEW YORK TIMES
Whitney Sudler-Smith resurrects’70s-era New York in his documentary,‘‘Ultrasuede.’’