Director R.J. Cutler makes the final cut

Dressed in a plain black T-shirt and faded jeans, documentary filmmaker R.J. Cutler hardly cuts an impressive fashion-forward figure.

But his blissful ignorance about bubble dresses or peasant skirts did not stand in the way of convincing the elusive editor-in-chief of American Vogue Anna Wintour — also dubbed Nuclear Wintour — to let him spend more than seven months trailing her stiletto heels. One of the highlights of the inaugural Doha Tribeca Film Festival, Cutler's documentary The September Issue offers you a glimpse into Wintour's world and her process of compiling the 840-page September 2007 issue of Vogue.

Cutler, whose credits include A Perfect Candidate about a Virginia Senate Campaign and documentary series American High, talks about his sphinx-like subject Wintour, the bitchy world of fashion and his greatest influences.

How did you get access to the fashion world, which is famous for not letting outsiders in easily?

I suspect many of my answers will surround the counter-intuitive. The reason I had access is because I asked. Many may feel fashion is famously inaccessible. But to me, it was not inaccessible at all. I don't know why Anna — in a certain point in her life — wanted her story to be told. But even before our first meeting, I think she had already made up her mind about the documentary and was OK with the idea of me observing her for more than seven months. Also, when you ask somebody out for dinner, you never ask her why she said "yes" to you. It's best to leave it untold.

Do you think Wintour decided to tell her story when rumours sprang up about her shaky standing at Vogue? Was it a publicity stunt or the need to put things into perspective after The Devil Wears Prada?

It's not true that she had difficulty maintaining her standing in Vogue. The rumours came about when an unnamed source wrote a snide comment in their blog and it got picked up by the rest of the world.

Just because it has been said, doesn't mean it necessarily true. I mean, who would fire Anna Wintour? Only a dummy would do that. Si Newhouse [publisher of magazines including Vanity Fair, Vogue and The New Yorker] did not increase his family's wealth by being a dummy. How on earth can you fire somebody like Anna Wintour who is brilliant at her job? Trust me, she has no problem maintaining her position.

And to put The Devil Wears Prada into perspective, I met Anna in September 2005 and I filmed with her in 2007. While the movie came out in 2006. I did not even know Meryl Streep was playing Miranda Priestly in the film.

Did you choose the subject or does the subject choose you? And why fashion?

Who knows? Anna didn't call me first and it wasn't really about fashion. It was about Anna. She is this ever-present figure in our culture that no one knows a thing about. I was curious about her because there are not many people like her in the world, who dominate an industry like her. In the fashion industry, you get the feeling that you can't get anywhere without Anna. She has that kind of absolute power that fascinates me. Very few people in the world have it.

For instance, Michael Ovitz [the Hollywood powerhouse who served as a celebrity talent agent for two decades until 1995] enjoyed that kind of clout. He invented the idea of packaging and he is the reason why agents became so powerful in Hollywood.

How involved was Anna Wintour in the editing process?

She was not involved at all. The day I met her, I said if I was going to do this then I will need to have the final cut and complete creative control. Of course, I waited till the end of our first conversation to slip that in. In my experience, it is always better to get it out of the way. If I don't have the final cut, nobody is going to take the film seriously. And she is Anna Wintour and I knew she was famously controlling.

In my case, she was understanding and told me her father was a journalist and she was a journalist too — so she knew where I was leading.

So did she stick to her word?

When she saw the film she had — what she likes to call — suggestions. But we talked about her ideas but I did not make any changes to the film. I suppose, she had a different kind of movie in mind. But she did not see the documentary until it was done and I didn't make any changes either.

Do you think you managed to portray Anna Wintour differently?

Anna is caricatured regularly and she is almost like a cartoon. To some extent she invites it — when you see her in public she has always got the glasses and in winter she has the fur coat. She sits at a fashion show with her arms folded and she is so theatrical.

In my documentary, I did not pull any punches or hide any secrets. By the way, she is not the Meryl Streep in the Devil Wears Prada. She is much more powerful and she doesn't have to act like a baby to get attention. The world shifts with her gaze and believe me, she would never send her intern to get a copy of a Harry Potter book. It will be on her table with compliments written on it.

I did the unravelling with all honesty, but it is up to the audience to figure this question out.