For a self-described “gay man who is not interested in fashion,” Vanity Fair editor and scribe Matt Tyrnauer certainly nailed his mark on the catwalk with his first (and, yes, very fashionable) documentary film, Valentino: The Last Emperor.

“What drew me in was the relationship between Valentino and his long-time partner,Giancarlo Giammetti,” explained Tyrnauer. “Their story had never before been told. And I had never experienced two people so close; involved in a relationship so dynamic and of such longevity.”

Tyrnauer made a fly-by through San Francisco on Friday for what he called his “dog and pony” show -- an opening-night appearance for his film at the Embarcadero Center Cinema. He was also persuaded by his pal, Fine Arts Museums Trustee Trevor Traina, to participate in an earlier Q&A with SF Film Festival Director Graham Leggat at the de Young Museum.

Valentino, the film, was borne out of Tyrnauer’s reporting and research for a 2004 Vanity Fair article on Valentino, the designer -- one of the last reigning lions of sublime, hand-crafted haute couture.

“After spending time with Valentino and Giammetti, I realized how much I loved the high-Fellini nature of their collaboration, with the great city of Rome as their backdrop,” said Tyrnauer, prior to his museum Q&A. “For me, this is the stuff of obsession!”

“Fashion was merely the background of the film. This is not a movie about dresses; even though those dresses are works of art,” explained Tyrnauer. “This is about a universal story-- a love story that’s lasted almost half-a-century.”

Tyrnauer described Giammetti as the complicated, brooding half of that love story’s equation. Valentino? The icon possessed by a monomaniacal vision of beauty and gowns.

When he is being imperious (which on film, is often), Valentino comes off as a diva. But a delightfully devilish diva who knows he is being naughty. As Valentino impishly says in the film, he can’t help himself: “I love beauty. Is not my fault.”

Graham Leggat, Matt Tyrnauer, Trevor Traina and Fine Arts Museums Director John Buchanan at the de Young/By Catherine Bigelow

Tyrnauer shot 250 hours of film over a two-year period, the dénouement of which features the elaborate 45th anniversary celebration in Rome toasting Valentino’s career. Two months after that storied three-day celebration which culminated at the Temple of Venus in the Roman Forum, Valentino announced his impending retirement.

A natural-born star, Valentino, however, was not always delighted by the presence of the omniscient, ever-rolling camera.

Tyrnauer finally had to lay it out for the designer: “That’s when, as ‘director to star,’ I explained to Valentino that it was important for him to expose his passion as well as his flaws. Otherwise, he would end up as a very unsympathetic character.”

“Of course,” said Tyrnauer, drolly. “He didn’t listen to me.”

But Tyrnauer (amazingly, in his first at-bat as filmmaker) deftly paints a masterful portrait of Valentino. Warts and all: hauteur, compassion, imperiousness, humor, vanity and sheer talent.

“Both Giammetti and Valentino were very disturbed -- knocked sideways -- when I showed them the director’s cut!”

And because both men are used to warming up the canvas of the director’s seat on their tightly controlled image, the filmmaker applauds their bravery for allowing this cut to screen. But Tyrnauer not only raised all the funds for this film himself, he’d also hammered out an iron-clad “Final Cut” clause in his favor, too.

Because of that clause, relations were somewhat chilly last summer as the trio was photographed on the red carpet prior to curtains-up for the film’s world premiere at the Venice Film Festival. However as the film was invited to screen at Venice, this dynamic, and very Italian, designing duo finally sensed a whiff of importance in the air.

“The movie screened to a full house,” said Tyrnauer, setting the scene. “At the end, Valentino, seated in the balcony, rose to accept a standing ovation – and burst into tears.”

“Valentino and Giammetti are also businessmen. And for a limited engagement, documentary film, our numbers are through the roof,” said Tyrnauer. “In fact, we just beat out Monsters vs. Aliens at the box office!”

The trio are back on a solid footing, sharing a relationship of camaraderie and respect. As well as, fun. Valentino (whose six Pugs appear as comic co-stars in the film) is helping to judge the film’s Pug-o-Vision Fashion Contest (entries are due by April 16).

And Tyrnauer, a previous devotee of daily, dark blue jeans and blue dress shirt, has adopted some sartorial savvy from the great designer.

“Valentino finally said to me,” relates Tyrnauer, in his finest Valentino-esque intonation, “Matt, if I see you in that blue shirt one more time, I scream!”

(In his defense, Tyrnauer notes that those particular shirts were made-to-measure Borelli -- the finest in all of Italia).

“I think that ours was the only film set where people had to dress up every day,” says Tyrnauer, laughing at the memory.

Though he also admits that, had he’d known the arduousness of the task he was taking on two years ago, he might’ve reconsidered the situation.

But the spell of celluloid has taken hold of the young auteur. And Tyrnauer is on the hunt for the next great story: “However, it must be another person with whom I will enjoy spending the next two years!”

Valentino: The Last Emperor is currently screening for a limited engagement at The Embarcadero Center Cinema.