We Asked the 3D Cinematographer of *Billy Lynn's Long Halftime Walk* What Shooting at 120 Frames a Second Really Means

"The essence of filmmaking hasn't changed. A good cinematographer was good 50 years ago, and is still good today."

On December 1 and 2, the Beijing International Conference on Entertainment Visual Effects (ICEVE 2016) was held at the Beijing Film Academy. The Advanced Innovation Center for Future Visual Entertainment also brought in Demetri Portelli, the 3D cinematographer on Billy Lynn's Long Halftime Walk, to walk the audience through how the film was shot.

Portelli is a veteran of 3D. In 2012 he worked with Martin Scorsese on Hugo, which won the Lumière Award for Best Live-Action Film. In 2014, The Young and Prodigious T.S. Spivet, which he shot with Jean-Pierre Jeunet, won Belgium's 3D film prize and the Camerimage award for Best 3D Film.

Even so, working with Ang Lee on Billy Lynn's Long Halftime Walk felt, Portelli said, "like going back to film school to learn how to shoot a movie all over again."

Why 120 frames a second? Ang Lee gets asked this over and over, and his answer is that he wanted audiences immersed in the film, close enough to feel what the characters feel.

Portelli explained the choice in technical terms.

"Shooting at 120 frames captures more information, more data. If you shoot at 120 and project at 60 or 24, the result is still very good, because one of the hard things about 3D for us is flicker and judder. At 120 frames each frame carries very rich information, and playback is very smooth."

In fact, even in a top-spec theater, not everything you see is 120-frame footage. Parts of the film were finished in post at 60 frames or at 2K. Some of the love-story scenes are 2K, and in the memory sequences, when the unreal figures appear, the specs may drop to 60 frames and 2K.

Portelli quoted Ang Lee on wanting to see his actors' eyes. "When he was shooting Life of Pi, Director Lee said he wasn't sure about 3D — at 24 frames he couldn't see the actors' eyes. He realized there were technical problems, and he wanted a higher frame rate so that in a close shot you could see the actors' eyes. That matters a great deal. Director Lee doesn't want to work below 120 frames anymore. His next film is also meant to be shot at 120. He took a very bold step and showed everyone that this was possible."

On set, Portelli put unusual weight on planning ahead. 3D is only one piece of the camera department's work, so the handoffs have to be sorted out in advance — he prefers prime lenses to zooms wherever he can. Plan it well, he said, and the 3D camera schedule stays in step with the 2D schedule and the shooting process, with no loss of efficiency.

Better tools made the shoot easier. In the office they used a lot of laboratory equipment, with good protective systems and air conditioning to cool the gear down. Billy Lynn produced 420 terabytes of data in all, which needed higher-grade storage to hold it. For the shoot itself Portelli used 3D camera rigs from a German company: "Their rigs are mechanically very good. You don't need any conversion or fixing in post, because the rig can be customized directly, or built to order to meet what we need."

"Success in 3D isn't like 2D. Testing the props and organizing the shoot matter enormously."

Portelli did admit that 120 frames, 4K and 3D together deliver an enormous amount of sensory information, which puts a heavy load on the audience and changes how the film feels to watch. And because the format shows every last detail — "especially in a facial close-up, where you can see the texture of a person's muscles and how they move" — an actor's performance can look overdone, and makeup is easy to spot. "So what we had to do on this film was keep the environment natural."

He still believes in where the technology is going, and he thinks the most important thing for an artist is courage. "When I was working with the 3D camera crew, Ang Lee told us we had to be brave and try it."

After the conference, Portelli sat down with QDaily. The interview follows.

Q = Reporter P = Portelli

Q: What was it like working with Ang Lee?

P: Wonderful. It felt like going back to film school to learn how to make movies again. He behaved like a student, learning how to shoot, how to live. He was a joy to work with — full of ideas, very democratic, letting everyone choose together instead of ruling on things by himself.

Q: Why use Billy Lynn's Long Halftime Walk for this new technology?

P: Billy Lynn is a book, a well-known one, and the studio wanted to make it because it's a very interesting story. Ang Lee loves shooting in 3D, and after Life of Pi he liked it even more. Once he finds a new technology, a new tool that can tell a story in a new way, he works hard at how to make a better 3D film — how to shoot faces better, how to shoot eyes better. On Life of Pi he ran into problems, like the image going soft when the lead moved, so he picked a new frame rate: 120.

Q: So it didn't have to be Billy Lynn for the experiment — that just happened to be Ang Lee's next film? Could any film have been used?

P: Yes, it could have been any film, the way Peter Jackson picked The Hobbit to try out a high frame rate. All of them — Peter Jackson, Ang Lee, George Lucas too — are pushing new technology forward.

We ran a lot of tests: texture, light, lens speed. The whole crew was testing, working out how to shoot at 120 frames. Billy Lynn is a good film at any frame rate, but it's better at 120, so why not try the new technology?

At first we hadn't settled on a frame rate — it might have been 60 — but in the lab we found 120 performed best, so Ang Lee decided on 120, which would make the film a masterpiece. We had thought about trying more than that, cross-cutting between multiple cameras and so on, but among all those complicated technical changes, 120 frames was the cheapest option.

Q: What you see on the monitor is 60 frames?

P: Right. No camera lets you see the 120-frame image directly on a monitor, but the 60-frame 3D already looks quite good. We checked partway through how things looked at 120, and it turned out to be striking — the film had far richer detail. That wasn't a problem.

Q: What did the testing involve?

P: Testing was very important. We went out together and gave them a taste of what shooting a film is really like — climbing mountains, shooting some footage and bringing it back — so they could feel whether there were any practical problems in the process. That way, before principal photography started, everyone knew what they were doing.

Q: Some people say Billy Lynn is so real it comes out unreal — the blood doesn't look like real blood.

P: That's a question of representation. We tried to represent things better. When you change the usual format, audiences really do feel uncomfortable. And the big screen is bigger than what you see in daily life, with more detail, so how do we make it look more real? That's our job: to represent things from life, differently from before.

Q: So what did you do to make the image look more real? Take the blood.

P: We tested a lot of different blood for color and for how it read in 3D on the Sony cameras. At one point the actor playing Billy Lynn brought his own blood packs, so during the take everyone gasped — my god, his blood is everywhere — but that created a problem, because the color was wrong on camera. We already had blood prepared in the right color.

Q: How would you describe what you do across different films?

P: It varies. Sometimes I'm the cinematographer, sometimes the director of photography. On Billy Lynn I was the stereographer. You take full responsibility for the 3D side of the shoot. Audiences love 3D because it excites them: in 3D they get scenes that rocket up and plunge down, and it looks better.

On a 3D shoot my main job is support, in production and in post. A high-quality piece of work needs a high-quality team — not just good tools and good technology but, more than that, good people.

Q: So a stereographer is different from a cinematographer?

P: The lead cinematographer is very busy; he also has lighting and other things to manage. I'm busy too. The stereographer builds the 3D image, and that takes a whole workflow to manage, shoot and produce. A 3D shoot needs two cameras running on set at the same time: what you shoot is 3D, what you watch on the monitor is 3D, what you hand the editor is 3D, and anything that isn't right you can fix on the spot.

You can also shoot 2D on set and make the 3D in post, but then you have to imagine the effect on the monitor while you're shooting, and you won't see the real thing for six months. That's the very technical part. Technology is the foundation for everything; only once it's right do you think about the art. That's the interesting part.

Q: Some 3D films are shot and finished entirely in 3D, but audiences still choose the 2D version, and theaters still screen 2D. Do you think about that while you're making the film?

P: As an artist, you have to answer for the work in front of you. You shoot a 3D film the way it will play in a cinema, and you think about color that way — you don't shoot a "television movie" just because it might also air on television. A 3D film does get shown in 2D, but when you decide to make one, you choose 3D lens work, 3D color and the rest. I'm not saying 2D is bad, but the film was made for 3D from beginning to end. It's like an oil painting: you should go see it at the exhibition, because seeing it in a book is never good enough. The artist chose to express it that way, so you should experience it that way. It's a very different thing.

Q: For most audiences, 3D means films like Avatar. Has much changed since then?

P: Yes, a lot has changed. From Avatar on, films were shot in 3D, and the whole industry changed — in China too. Before that, nobody was running two cameras at once.

Q: Has the shooting process changed?

P: Not much. It's close to a 2D shoot, with a few more hands and a better schedule. It's different from shooting on film — film is expensive, so you had to keep cutting, and actors would ask, can we cut for a second? I need a break. Now the digital cameras just keep rolling, which makes it feel a bit more like shooting a reality show.

Q: So the process hasn't really changed.

P: Right. However many days a 2D shoot takes, we can do it in the same time in 3D; we just have to communicate a little better. What's different from 2D is that you can't pack up the camera gear and move straight to another location. So you need a very good schedule — everything arranged and in order, rather than making everyone wait on your pace. 3D doesn't take longer, but it takes more thinking up front, and there are more constraints in post.

Q: Do all directors know what they're using 3D to say?

P: No. A lot of directors are just caught up in the commercial scramble, choosing 3D for the box office or to make the film look impressive, and that makes me very sad, really very sad. Because as a director you should know exactly what the tool you're using means. Spielberg, for instance, studies 3D all day, because he wants to make a good 3D film. But directors still work toward a 2D result.

Film technology is moving fast, maybe a little too fast. To an audience it looks like a new technology shows up every year.

VR is the hot topic now, but 3D wasn't common two years ago either, and no film has been turned upside down by it yet — it just gives films a few more things to express. The essence of filmmaking hasn't changed. A good cinematographer was good 50 years ago, and is still good today.

This is about filmmakers, about the story, about how they present it to an audience. They should try more; they have to be creative. From the storyboard on, you should already be thinking hard about how to present things in 3D. How you present something is storytelling, and storytelling is art. A lot of directors who want to work in 3D think that setting one object behind another, or controlling the light in a room, is in some sense already a 3D technique — and 3D can give a shot more information, more content, and with more content you can tell the story better.

Q: I've heard that 120 frames, 3D and 4K have completely changed how films are shot. Is that true? How much has changed?

P: I think the change is that you have to think about how the actors should move, and there's probably more to think about in post. For me it hasn't changed that much; shooting a film is still shooting a film. But the set has to be very strict — you can't put junk on a wall, because it will be plain to see. Everyone has to work better, in more detail, with no cutting corners. The actors in the background can't do anything careless either, because it will be plain to see. You have to pay more attention and be more careful.

Sometimes you do very good work, you shoot a very good film, and people watch it on a phone, and that's a shame, because you can't see what makes a good film beautiful. Some technical changes are the right ones; they make a film more beautiful. If you find your film has become more beautiful, that proves the change was right.

Hitchcock was already doing 3D sixty years ago. The technology is quite mature by now; it's only in recent years that it's been widely used.

China is the biggest 3D market, but Chinese 3D films are especially bad. If you ask me, Chinese audiences badly need high-quality 3D films, and that matters. Because I hate people spending very little money to make very poor 3D and selling it to Chinese audiences. Keep selling bad 3D films and you'll ruin the business, because 3D tickets are expensive. So the reason I'm here is that I want to push better, higher-quality technology out into the world.

Q: Do you think other technologies will change your work much?

P: I think a stereographer has to keep an open mind, but making a film is making a film — technology is only a means. Maybe there will be changes, VR for instance, but I don't know; I'm still learning about all this. These new technologies have more to do with your brain than your eyes. What the brain feels matters more.

Cover image: a still from Billy Lynn's Long Halftime Walk