Fire and fury: behind the walls at Vogue

“I almost felt empathy for her,’’ she told Cutler, who was in Boston for a question and answer session about the film. “There was a point where you could see how hard her job is and how much pressure she’s under. I actually felt bad for her.’’

Cutler’s film, which opens here tomorrow, follows the eight-month period leading up to the publication of Vogue’s biggest annual issue - the September issue. Cutler and his crew were given unprecedented access to Vogue’s creative staff, including Wintour, who, in her 20 years at Vogue, has become a revered and feared figure in pop culture. She’s said to be the inspiration for Meryl Streep’s Miranda Priestly in “The Devil Wears Prada’’ and the mysterious Fey Summers of “Ugly Betty.’’

As the action follows the artistic tug-of-war involved in putting the magazine together, creative director Grace Coddington emerges as a worthy adversary for Wintour. It’s a compelling story that Cutler was inspired to tell after reading a profile of Wintour in New York magazine. The director, whose credits include “The War Room,’’ and who admits that he’s far more interested in politics than fashion, said his mind was made up to work on the film shortly after meeting Wintour.

“After I met Anna and spent some time with her I knew that this was something I absolutely wanted to do,’’ Cutler says. “This is something I wanted to devote two years of my life to and wake up screaming in the middle of the night over.’’

During the first meeting, Cutler explained his filmmaking process to Wintour. It is purely observational with occasional interviews with the main players - in this case Wintour, Coddington, and Vogue’s larger-than-life André Leon Talley. It was also during this meeting that Cutler explained that in order for the project to be successful, he would need to have final approval over the film.

“I told her that as far as I was concerned no one would take a movie about her seriously if the director didn’t have final cut,’’ Cutler recalls. “She told me that she totally understood. She said her father was a journalist, she said she is a journalist, and she totally understood. It was right then I thought, ‘Oh my God, Anna Wintour talks. I have been here 15 minutes and she mentions her dad to me.’ That’s when I knew I really had something.’’

Many of the questions that Cutler fields during his “September Issue’’ promotional tour revolve around Wintour, but during the course of the film, the straight talking Coddington threatens to steal the documentary out from under Wintour’s fur coat. After passionately styling a series of jaw-dropping, ethereal fashion shoots, Coddington watches with quiet fury as Wintour edits out several of her favorite pictures.

It’s an important part of the film that almost didn’t exist.

“We were going to be there for eight months, and Grace Coddington was not happy about it,’’ Cutler says. “I think angry is a better way to describe it. She wanted nothing to do with us. She avoided us for the first four months. But we talked, and once Grace agreed to do it, she really opened up. It just took a while to earn her trust.

“But it was essential that we have her in the movie,’’ he continues. “Grace Coddington changed the way that we think about fashion photography. And anytime she and Wintour were together, sparks flew.’’

The designer Thakoon, best known for creating many of Michelle Obama’s dresses, appears in the film as his career was beginning to blossom in 2007. In the movie, he describes how his hands shook the first time he met Wintour.

“I think people get nervous around her always because she’s so influential and powerful - and she’s not warm,’’ he said on the phone from New York last week. “But she has shown me a lot of support because I’m vocal about my vision and what I do. I think she respects that. Once you get to know her she’s enormously supportive, and she cares a lot about what she does.’’

Cutler clearly respects Wintour and her command over the $300 billion global fashion industry. He bristles when questions turn to Wintour’s notoriously icy persona.

“She’s not a fictional character. She’s not a caricature or an outburst-oriented character who gives theatrical monologues,’’ he says. “It’s such a weird question when people ask if she’s anything like Meryl Streep in ‘Devil’. I don’t understand it.’’

But ultimately, what Cutler is interested in is not defending Wintour, but making an entertaining film.

“People will come away with a greater appreciation of fashion - how can you not when you’re watching a pair of legends?’’ he asks. “But my objective is to make a great movie and tell a great story. That’s really all I think about.’’