Many of Liz Garbus’ documentaries—such as 2011’s Bobby Fischer Against the World and 2015’s What Happened, Miss Simone?—examine highly public figures and make generous use of stunning archival footage that puts the viewer squarely in the middle of the story.

Garbus’ greatest gift, however, is her ability to bring new insight, empathy and reliability to seemingly well-known subjects. Miss Simone, for example, gave us an unprecedented look at iconic American musician Nina Simone, from her vibrant public life to her innermost private struggles. This year, Garbus directs this same intense, insightful eye toward another American icon, Gloria Vanderbilt, and her equally famous son, journalist and news anchor Anderson Cooper.

Nothing Left Unsaid traces the life of heiress Vanderbilt from childhood through the current era. It touches upon her complicated upbringing, her many marriages, her career as an actress and businesswoman and her time as a mother. The film also brings to light Vanderbilt’s lesser-known passions and habits (her love of painting, for example) and the many tragedies that shaped her into the woman she is today—like a bitter custody battle that loomed large over her childhood, and the tragic death of one of her sons.

As the title of the film indicates, Cooper and Vanderbilt are incredibly close; the pair actually came up with the idea for the documentary themselves, before HBO tapped Garbus to tackle it. We spoke to the accomplished director (twice Oscar-nominated, for The Farm: Angola, USA and Miss Simone) about her latest project, the difficulty of working with famous subjects and the barriers facing female filmmakers today.

Amanda Meyncke, MovieMaker Magazine (MM): What attracted you to this story, especially since the subjects already have such a public history? In one sense, it feels as if it’s a topic we already know very well.

Liz Garbus (LG): HBO brought the film to me, as something Anderson Cooper was interested in doing. At first, I thought, “Wait, they are so public; what is it that I have to say about this story? Why me? Why should I tell this story?” And then when I met with Gloria and spent time with the two of them, I felt like I was being let into a world that people really didn’t know. Gloria’s life, at least today, is very solitary, very quiet. She spends her days mostly going up and down stairs between her studio and her apartment, and they celebrated her birthday with peanut butter sandwiches. It’s a different life, and one that’s more relatable than we had thought. I found Gloria to be a wise human being and her art to be so narrative, and from a filmmaking point of view, it was a very interesting opportunity.

Gloria Vanderbilt Cooper relaxing with her family in her NYC apartment, she is wearing a sailor collar and tie by Adolfo *** Local Caption *** Gloria Vanderbilt;

(L-R) Carter Vanderbilt Cooper, Wyatt Emory Cooper, Anderson Hayes Cooper and Gloria Vanderbilt in 1972. Photograph by Jack Robinson/Vogue; courtesy of HBO

MM: How long was the process from inception to delivery?

LG: About two years.

MM: Is that average for your work?

LG: That’s about how long it takes. We really do edit for quite a while and with a film like this, where the archive is so vast, it’s not unusual for a film to spread out over that time.

MM: When you’re making a film and there’s so much archival footage available, how do you begin to go through it?

LG: When we’re going through the interviews—in Nina Simone’s case, that was going through audio material I found of her; in this case it was the interviews between Anderson and Gloria, interviews I did with Gloria—I’m looking for the stories that carry the soul of the film, or the person, or the moment. The archival footage becomes a visual expression of those stories. With Nina it’s a little bit different because some of the archival footage was important scenes that determined the story. In this case, there were expressions—Gloria would talk about memories—and so we were very story-driven in that sense.

MM: Working with famous subjects is so interesting—they seem familiar and yet before the documentary, I didn’t know Anderson Cooper was Gloria’s son!

LG: When HBO called me and said Anderson Cooper wanted to do a story about his mother, I said, “Who’s his mother?” I think that’s good; if I had too many preconceived notions about them I would have experienced them differently.

MM: How much control do famous subjects exert over the films?

LG: In any documentary film, whether it’s a famous person or somebody you have met in a grocery store or in a prison, or wherever my films have taken me—you’re asking them to share something very, very private and very vulnerable. You do have to allow them space. If they don’t want to talk about something you don’t force them to do it. In this case, these guys were very, very willing to go there. Obviously they signed up for this film; they wanted to have these conversations. For instance, with Gloria talking about the suicide of her son, it’s something that for her makes her feel like he’s present. It’s not something she goes away from. As Anderson said, he grew up with the language of loss. So some of the things I think we run away from, she didn’t. There was never a request from Anderson or Gloria—“Talk about this, don’t talk about this,”—there was never any meddling.

MM: Is there any thing absent from the film? Is this the story you fully wanted to tell?

LG: When you’re dealing with a life as exciting and expansive as Gloria Vanderbilt’s, there are chapters one would like to explore if you could make, for example, a 10-hour version. I do think the film expresses who she is and the relationship that I got to see. It is the heart of what I found to be really special about them. It is a love letter of sorts and I hope it inspires other families to come together, have those conversations and not be stuck in old patterns of “We can’t talk about this,” or “We can’t go there.” I think it is freeing and I think it makes us live a more considered life.

MM: Even the phrase “nothing left unsaid” is so beautiful, such a powerful statement of love between two people.

LG: I think that’s what really drew me in when I first was with them together: how their lives have been extraordinary but in many ways their relationship is ordinary. When I walked in that first day with Anderson into Gloria’s apartment, she greeted us all very warmly, but then immediately put Anderson to work on trying to fix a lamp that didn’t work. It was very relatable and I think people think their lives are so different from ours. And of course, having money and privilege does make it different, but then in other ways, there’s something universal there.

MM: You’re very careful to use a lot of movement-oriented clips in your work, and in this film with the paintings becoming animated and so on. Is that an intentional choice when you started making docs or did you come into it? 

LG: That’s interesting. People are always pointing out things to you that you’re not necessarily conscious of. Certainly, I work with wonderful cinematographers, and one doesn’t want one’s films to feel static. I’m not a fan of “locked-down.” We have talking heads in this film for sure, but we tried to keep it incredibly alive and used animation to create the beautiful spaces that the viewer could be in while hearing these painful but often beautiful stories.

MM: I noticed that you’re not as present in your docs as other documentarians. Is that intentional?

LG: I think any time you watch any movie, you’re seeing 90 minutes of reality filtered through the director’s lens. I have not chosen to be on camera or especially vocal in my films. I’m not against it, but I haven’t felt it would add anything to the particular stories I’ve been telling.

MM: What draws you to documentaries? What do they hold for you that other types of filmmaking lacks?

LG: I don’t feel that narrative filmmaking lacks anything. Sometimes truth can be stranger than fiction, and it can be wonderful to work within the confines of the truth and yet weave stories and meaning through the complexity and chaos of reality. I am also drawn to narrative filmmaking; I’m drawn to storytelling. Every now and then I’ll see a great movie and it’ll change me a little bit, the way I live—it could be a documentary, it could be a fictional movie. That’s what I like to do. Is there some humanity that makes us live a little more kindly with a little more understanding, a little more humanity because we now understand somebody or something we didn’t before? That, to me, is the goal.

MM: Does having an Oscar nomination make things easier as a filmmaker?

LG: Getting your film to that space, whether it’s nominated or it wins, is enormous exposure for it, and validation. People who don’t necessarily watch documentaries will decide to watch yours and it really becomes part of a very national conversation.

MM: What sort of advice would you give to film students who want to be documentary filmmakers?

LG: When I have film students reaching out about ideas about documentaries, what people really need to ask themselves is: “Is this a movie?” Sometimes people have ideas and they think it’s an important issue, and maybe it’s something that would be great in an article. Is it something you’d want to sit in a theater for 100 minutes? Granted, I know most people are seeing things on a small screen—but I still think it’s a good test. Does it have the visual and narrative depth and breadth to sustain that? It’s really about examining your story and what kind of legs it has. Because there can be an interesting character or issue, but that doesn’t make it a movie. You have to ask yourself that question really hard. People pitch me ideas all the time, and I’m just like, “I love that—I’d love to read an article or see a short film of that.” But a [feature] documentary? You’re asking someone for an evening of their life, and it’s got to be meaningful.

MM: What are some of the biggest barriers to female filmmakers?

LG: The barriers are enormous, because in some ways they’re visible and in other ways they’re very invisible. You can have a certain level of success—get a movie into Sundance, for instance—but then that next level of getting plucked out to make your next film at a bigger budget level? You don’t even know it, but it’s taking you five times as long as it’s taking the dude who made their first film that year too. These invisible ways are the ones that are harder for women. I think the conversation that’s been happening has mattered. People are starting to get concerned about who they’re hiring to direct TV shows, and about what the gender balance is on their slate of movies that year. It is making a difference. Frankly, for female filmmakers, they just need to keep on making all the kick-ass work that they’re making. It hasn’t been their problem, and in some ways that’s not an empowering thing because there’s not much more they can do except keep making the good stuff. It’s more about the industry recognizing them. It’s about having these conversations. It’s not really about what we can do, because we’ve been doing it. It’s more about the next steps in the industry, and the conversation has been happening and I feel it trickling through.

MM: What’s your personal favorite documentary?

LG: I have so many but, I’ll go back to The Thin Blue Line by Errol Morris. I love the idea of making a film in this hidden world, having the kind of impact it had on a human life, and the visual creativity of that film. Now it’s in vogue to have the true crime story, but that was the classic, beautiful example of that. Everybody should see The Thin Blue Line. MM

Nothing Left Unsaid premieres April 9, 2016 on HBO.