Yes, ‘Dune’ used sandscreens, but it also used grayscreens, and even bluescreens

Visual effects supervisor Paul Lambert discusses more about that side of the filmmaking.

Following the release of Denis Villeneuve’s Dune, befores & afters got the chance to sit down with visual effects supervisor Paul Lambert, and DNEG visual effects supervisors Tristan Myles and Brian Connor. One of the keystone aspects we discussed was the fact that special ‘sandscreens’ were erected in the filming location of Budapest in place of what would normally be bluescreens or greenscreens.

The sandscreens helped maintain the desert environment feel for the actors and filmmakers, avoided bluescreen spill, and had the added benefit of actually having bluescreen-like keying properties once inverted as a negative image.

That side of the visual effects production generated so much interest in the initial b&a story, that I asked Lambert if he might elaborate further on the process.

b&a: So let’s recap what’s actually going on here. Many films use bluescreen and greenscreen and I would say there’s a bit of a view on all that at the moment, where I think directors and actors, they don’t necessarily love bluescreen and greenscreen, even though it clearly is used a lot and has a real purpose. Here on Dune, you had so many scenes on this sand-covered world, and you had a director that maybe doesn’t like blue or greenscreen. So how did that sandscreen thing formulate in your head at an overall level?

Paul Lambert: Well, I knew that Denis wasn’t a fan of blue or greenscreen, if anything, it depresses him. Denis, when you hear him talk, he’s all about the human interaction with nature and I don’t just mean pretty vistas, but I mean structure and the like. His captivation with brutalist architecture and that kind of thing is all about your interactions with that world around you. And that’s very much his basis, he wants his sets and he wants his actors to feel in that world.

On the ‘sandscreen set’.
When the image is inverted, the sandscreens turn to a suitable color blue that can be used for keying.

There was a great discussion recently with him and James Cameron about their processes and Denis actually goes into this about wanting actors to feel that they are in this world. We used sandscreens for Arrakis and Arrakeen, but we also used grayscreens for Caladan interiors and a gray with a very slightly blue tint for Caladan exteriors.

We actually used bluescreens for Salusa Secundus. So, it wasn’t that there was this one color only. Basically it adapted to what the backgrounds were going to be. Because the Salusa was definitely going to be in this more gray/blue world. It did change on the morning of from a gray surround to a blue surround, but because we were having SFX rain and that kind of thing, I deemed it necessary to actually go with a more traditional blue. In all these worlds when we had a view from the inside to outside we would use bright white screens to simulate the relative outside exposure.

The idea was that in thinking through what our backgrounds and what our worlds were going to be, and also coming from a compositing background and knowing how imagery goes together–a foreground and a background–I knew that just as long as you have a constant color behind your foreground talent, that there’ll be a way to composite that onto a new background.

See, the really great thing about Dune was that because Denis had spent all this time doing concepts, we knew what the backgrounds were going to be. We were never in a situation where it was, ‘We’ll figure it out later in post.’ It was always going to be a case that, ‘Okay, we’re doing a shot, I know what’s going behind it.’ So that allowed us to say, ‘Okay, if it’s going to be Arrakeen, we know it’s going to be sand color or it’s going to be desert or it’s going to be that color.’

b&a: And then with the actual sandscreens and the color itself, how did you come to that?

Paul Lambert: I started to experiment with this idea and I brought out two compositors with me to set during pre-production. I had a previs team who could do all of the additional 3D extras I needed, but then I also specifically brought two 2D people out so that we could do testing to help inform the shoot. And one of the tests we were doing was that, okay, if we decide to go with a different color background, let’s test this because it’s actually a big deal to suddenly say, ‘Okay, I’m not doing this with a traditional chroma or digi blue color, but I’m actually doing these other colors.’ So quietly, we did these tests because I didn’t want to announce anything until I was sure.

Inside the ornithopter cockpit, with sandscreens on the outside.
The ornithopter image is inverted.

I got one of my onset compositors, Mag Sarnowska, to get some material, shoot some of the PAs and coordinators with long flowing hair up against these screens and do some tests. And I’d sit with her trying to come up with the procedure and that’s where we figured out, ‘Okay, look, if this particular color…etc etc.’

The driving force wasn’t that the inverse of the sand color would be blue, which we talked about last time. It was the fact that it was a constant color and that light would be the bounce light going onto people; that would be the benefit of this. But then we found, okay, look, but we can actually either convert the image and pull the key. Either by inverting the image and pulling the key, or we can swap out a couple of channels, swap two channels, and it would, again, become something useful that way.

Now, obviously, if you shoot me up against a sand-colored screen, my flesh color is going to be problematic up against that screen. So it’s not like this was a brand new magic color meaning you could just place anything into that world with the push of a button. Still, the sandscreens had a multitude of benefits, one was the fact that it kept Denis happy, and politically also. And another big thing I found here is that when you erect a bluescreen, certain parts of the on-set crew can switch off because it’s going into post, you know what I mean? The age old adage of ‘fix it in post’ suddenly becomes a reality. By having these screens of a different color it became more of the physical set rather than just a post thing. Obviously I got questions from the onset crew about it so a simple explanation of how its a representation of what we will be adding in post goes a long way.

b&a: Paul, let me tell you something about this, which is why I loved it the first time you mentioned it as well. This is going to sound a little ‘niche’, but I see a lot of EPK b-roll for making-of stories. What you’ve just said about the bluescreen thing and greenscreen thing is fascinating on a different kind of level, because sometimes in those EPK b-roll reels, they will grade down the bluescreen to be gray. They weren’t gray screens on set, but I think sometimes it’s about not revealing that VFX was a big part of the filming, or not kind of distracting from the b-roll action with the actors.

Paul Lambert: Well, that’s funny because when I saw some behind the scenes videos people have made about Dune, somebody has put together a mock behind the scenes, and on the icon, somebody has roto-d out Zendaya and Paul, and put them on a greenscreen.

b&a: I know. I know.

Paul Lambert: I said, ‘I didn’t shoot like that!’

b&a: I know. I mean, there’s a couple of YouTube channels, they’re behind the scenes channels, they’re notorious for the thumbnails being greenscreen or bluescreen mockups, but they’re fake.

Paul Lambert: It’s like, I couldn’t believe what I was looking at. I thought, there’s no greenscreen.

b&a: That’s so funny you noticed it. I was talking to some VFX artists about this just the other day.

Paul Lambert: It was funny, really.

b&a: So sorry. Back to what you were saying.

Paul Lambert: So, another aspect of having these sandscreens, was the benefit they had for non-visual effects shots. For example, reflections in visors. We would shoot the soldiers with visors and you’d see in the reflection in their visors a sandscreen–but really just the sand color–and the sky. Having that surrounding the set, and then having all these visors, it just worked. I didn’t take off any visors. And having the ornithopters with glass. I didn’t remove any glass. Having diffuse metal reflections basically allowed me to have shots like this, where it wasn’t a visual effect shot, and it would never be budgeted as one. But if I had a bluescreen out there, there’d be blue in it, and it would need to be de-spilled and it would be a thing done in DI, unless specifically requested by Denis. But there is no way that that would be budgeted for as a digital effects shot.

So there were numerous occasions where we captured just a little bit of a reflection and it feels like you’re in Arakeen or the desert, because it’s the sand color and the sky. That was another intention for the sandscreens.

b&a: I love it. I mean, I felt like that occasionally with First Man as well in terms of reflections in visors or in cockpits. [Lambert was the visual effects supervisor on the 2018 film]

Paul Lambert: That was actually the driving force. Because what I found on First Man, because Damien Chazelle the director wanted such long clips, which were constantly playing in the background, you would get shots, which would never, ever be budgeted for visual effects. But then you were getting the reflection of what was happening in the background, on the dials of the Apollo module, and it just added to the believability of it all.

b&a: And then part of the fun of the sandscreens was that you could do the inverse of the sand color and it looks like a bluescreen. Last time you were showing me that on your iPhone, but did you make that kind of discovery during the test phase? Or was it more once you got on set, that you noticed it could be inverted on your iPhone?

Paul Lambert: [Shows b&a an on-set image from the Budapest shoot]. So, that’s part of our Budapest backdrop, which if you invert it, suddenly everything becomes blue. Obviously you can see the issues with some of the skin tones, but it gives you an edge, and you realize it’s a compositing solution where you can come up with all the different techniques to be able to pull that off.

b&a: That’s amazing. I think, as you said, it’s not the main reason for using the sandscreens, but it’s such a useful thing you discovered.

Paul Lambert: For sure. And once I realized that, in working with my on-set compositors, then that’s when we then started to play with the colors, what would be the ideal blue and still feel like sand? And that’s where we then got cloth and wood and metal and all sorts of things and got people to dance around in front of these screens and wave their hair around. So once I’d got that down and then I had presented it to the other heads of department–I didn’t mention the inverse to the bluescreen. Because basically, I needed to get budget approval to paint the whole backlot this sand color.

And I explained the fact that, yes, we could see it in reflections and we could see that bounce light and that kind of thing would be really beneficial. And Denis loved it. Now, honestly, there was a whole bunch of roto but you always get a whole bunch of roto with bluescreens anyway.

The ‘Dune’ visual effects team used sandscreens instead of bluescreens

b&a: I was going to ask you one other thing about the sandscreens, in relation to immersing the filmmakers, the crew, and the actors in the scenes. Do you think that could go further with any other kind of backing? Would you even consider a more virtual production side of it, ie. LED screens? Is that just as viable here, or is it not as viable?

Paul Lambert: Well, all the sandscreen work was outside. So having an LED screen isn’t really going to work for the kind of exposures in which we’re doing. But it’s like horses for courses, whatever tool fits at that particular time. Working with Denis, we’re never going to have a situation where the technique is going to define how we shoot the movie, it’s always the other way around. What’s the intent? And then trying to figure it out, which I love, that way of working. But yeah, obviously with LED screens, the idea is to have the final pixels behind you.

But I’ve been hearing so many scary stories about things which are getting changed in post after the fact, and I think, oh, well, what the heck do you do with the edges then? It really helps to know what the background is going to be. It really does. And it’s no fault of anyone, really. Decisions can be made in post by clients and there isn’t much you can do about it. There will be a day where we’ll be able to shift certain things with AI, but we’re not there yet.

We did actually do an LED screen for one particular sequence, which was going to open the movie, but it got cut because I think that there was a movie which came out and it had a similar kind of thing of somebody falling to earth, it was that Brad Pitt movie Ad Astra. It was a sequence with Jason Momoa, where you got to see him land on Arrakis, and basically we shot him against the planet, on this massive LED screen, but it didn’t make the cut.

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