Recently Paul Franklin, Visual Effects Supervisor on Inception, and one of the founders of London-based effects house Double Negative gave a talk at the Apple store on Regent Street to promote the forthcoming release of the Blu-Ray Boxed Set of Inception (available to pre-order now).

The day before hand, HeyUGuys were fortunate enough to get an interview with Paul. During the course of which we discussed how VFX have changed over the last few years, Paul’s favourite film, and how they managed to pull off Inception’s amazing zero-g sequence.

HUG: So you were the VFX [Visual Effects] Supervisor on Inception, and your role at Double Negative is?

PF: Well my role is normally VFX Supervisor, but I’m one of the guys who founded Double Negative back in 1998. When we started out, we did a film called Pitch Black, that was our first movie, and at the time, I was the CG – Computer Graphics – Supervisor on that film. Actually Double Negative was ten people when we started out, and it’s grown steadily over the years, and we’re currently eight hundred people these days, and we’re doing about ten or fifteen shows at the same time.

HUG: Three of four offices round London now, isn’t it?

PF: Well we’ve got one really big one down the road, on Shaftsbury Avenue, most of the people are in there, five hundred odd people in there. There’s another two hundred and fifty over in Fitzrovia, which is where I work, in our new office, and then we have another studio in Singapore. We’ve got about fifty guys over there.

HUG: Could you explain exactly what the Effects Supervisor does?

PF: The Effects Supervisor is the head of the Visual Effects department, and is responsible for the design and execution of all the visual effects in the film. There’s another department called Special Effects, and Visual and Special Effects normally get lumped together by the general public, as ‘Special Effects’, but within film making, visual effects is everything that is generally worked on in post-production, and paid for out of the post-production budget. So it’s all stuff like computer graphics, green screen work, adding monsters, space ships, that sort of stuff, colour correction, wire removals, that sort of thing. Special Effects is all the physical stuff that happens for real on location. So explosions, crazy rigs, the Batmobile for example, that’s a special effect, built by Chris Corbould’s Special Effects department. When the Batpod comes out of the Batmobile, that’s a visual effect, because they couldn’t do that physically, so it’s all computer generated. Effectively, visual effects functions like a Second Unit for the film. Chris Nolan doesn’t work with a Second Unit, he shoots everything himself, but what we do is we go away and we shoot all of the things that you otherwise couldn’t see, creating them with our computers and things, but Chris treats us as if we’re just part of the film making process.

HUG: Do you spend anytime on the set during the process?

PF: Yeah, absolutely. My job on this film started right at the very beginning of pre-production. Chris phoned me up in February of last year, I was in LA. My whole family was there actually, for the Oscars for the Dark Knight, and Chris phoned me up; I was standing in the middle of Disneyland with my kids, and asked me to come in to read the script, which I had to read inside a locked room with somebody guarding the door. I got like two hours to read the script, and then he called me up immediately then said ‘Right, so where do you think the effects go?’ Then that conversation would carry on through pre-production, where I’m breaking down the script, working out every moment where an effect would be, what techniques we might use, how much it might cost.

I’m working with the other heads of department, collaborating with the Art Department to see what their designs for things are, with the Special Effects guys, so we know what kind of rigs they’re going to be building, and things that they can build for us, Stunt Department with all of that wire work we did in the film. So working with Tom Struthers, the Stunt Coordinator on the film, and even working with the Costume Department, and Camera Department, working out all of the ways they’re going to light things, and the way the costumes will look, basic choices like the colour, green or blue screens will be dictated by the colour of the costumes you’re shooting. There’s no great mystery to all that, I’m often asked ‘Why green? Why blue?’ If the guys wearing blue in the foreground, you put a green screen behind him, it’s that simple…

Then you go into production, shooting the movie, and Chris, he wants all of his HOD’s, Heads of Department, to be there on set, all of the time, or to be accessible, because there’s a continual ongoing creative discussion. You’re working on the film, and Chris might say ‘What about if we do this?’ or ‘We need to this here’, ‘Do you think VFX can remove that rig?’ or ‘What can you do to add this background?’, or ‘The lightings not right, what can we do to change the time of day?’ and that sort of thing. Then further afield, you’re looking at a location and he’s saying ‘Hey this would be a good idea, the way this building looks, it could be incorporated into Limbo City later on’, or he’ll see something like the way a helicopter is flying over head and there’s a vehicle sequence you want to base off of that, or an action sequence that might have that.

So that’s one reason why you’re on set. The other reason you’re on set is to make sure that everything’s filmed in the correct way, that you’re getting the right information, and people are doing things correctly with green screens, we’ll come back to that, have to be lit in a certain way. If they’re over exposed, or under exposed, they don’t really work. So you’ve got to just kind of sit there with the guys from the Camera Department and the lighting guys, make sure that it’s exposed correctly.

You’ve got to take lots of reference; when we were doing the Paris street folding over, there’s hundreds of thousands of photographs of those buildings taken, digitals photos, we did a digital survey of all the streets with a thing called a LIDAR, a scanner which is a sort of range finding laser device which scans it down to sub-millimetre accuracy, we built this very detailed model of the city. We were out in Canada, we’re constantly taking pictures of the mountains, and the changing weather conditions, so we then had material to stick into the green screen windows on the set, when they’re inside the base, so it’s got continuity of what you’ve seen outside. We’re constantly gathering information like that.

Another reason for that is that during post-production, when Chris is cutting the movie, he might suddenly turn around and say ‘Hey we need a shot that does this; we need to bridge this moment in the film with a new scene’, and we’ll say ‘OK great, what did you shoot?’ and the answer is ‘Well nothing’. So you’ve got to go and create it entirely digitally, so it’s important to cover yourself, document every location and take all of the details in case you need to recreate things.

HUG: So in terms of creating of creating entirely digitally, it’s computer modelling. How do you find, even over the existence of Double Negative, it’s changed phenomenally.

PF: It has yes. Obviously the great thing is that computers keep getting cheaper, or they get more powerful for the same price, which is another way you’re looking at it. The storage for it, just talking about hard disk space, our first movie, Pitch Black, we generated just under, I think, two terabytes, just under two thousand gigabytes of information for that film. We had a shot on the Dark Knight, which just in that one shot alone, was over two terabytes of data. Inception was about one hundred terabytes of data. So it’s a hundred thousand gigabytes of data.

The fact that the hard disks keep getting smaller and cheaper, and use less power, is a very important thing, and it gives us extra capabilities. Also the techniques have improved all the time. The software has become more and more sophisticated, it’s become easier to use. That has brought in more people into the business, because they see it as being more accessible. In the last ten years, we’ve started to see people going to Art School to actually study these techniques, rather than people like me, who went to Art School to do traditional art, then came out and found our way into it. Guys of my age are generally self-taught, in this business, because there were no courses you could study, but now, it’s a different kind of community.

About six or seven years ago, we reached a tipping point, where the kind of detail we could put into digital images matched that of film images and actual stuff you could photograph, so now it’s really increasingly difficult to see what’s been done in films. People can of course spot giant monsters running around, crazy superhero action, but the more subtle use of work in films is very difficult to spot.

We did a film for Alfonso Cuaron a few years ago, Children of Men, and that’s got hundreds of visual effects shots in it.

HUG: Did you do the in car camera shot?

PF: Yeah, exactly, that’s four different locations shot over three or four different days. There’s loads and loads of CG stitching that together.

HUG: You must find, looking back on things you’ve done previously, you must itch to go back with modern technology and tweak?

PF: Well it really depends on how good a film it is. My favourite film is the Korda brothers’ Thief of Bagdad from 1940. It’s got obvious blue screen fringes; it’s the first time a blue screen was used on a colour film in 1940. But they don’t matter to me, because the film itself has this fantastic self-consistent sense of fantasy. It’s completely seamless, as far as I’m concerned, about the way it works. Some of it looks very much of it’s time, there’s a flying genie that’s clearly a little model held in front of a cyclorama spinning behind it. It doesn’t matter, it wouldn’t improve it by doing it digitally, I don’t think.

HUG: When you describe blue screen and lighting fore-screen, you’re not talking back projection?

PF: No, an actual blue screen. They would use a photochemical process to isolate the foreground and replace the background to do that.

HUG: The shot in Inception, where everything goes zero-g. It’s seamless.

PF: That was kind of real old school stuff, because Stanley Kubrick had worked out a lot of this stuff for 2001, and one of the key things there, is the way that the set was built. So you’ve got the corridor set, and we had a version of it on it’s end, so the floor becomes the wall, and then the performers are dropped in on the set on wires from the far end of the set. The camera is on the floor looking up at them, so their pendulum type action, actually becomes them bouncing from walls to the floor to things, and that’s a much more convincing zero gravity look than if they’d shot it vertically, with the cameras looking sideways. The great thing also is because you’re looking up at them, the wires are behind them, so you can generally hide a lot of the wires, and then we paint out the other stuff.

The difference between 2001 and our film, is that 2001, because they were limited through various other techniques, it’s all very stately and sedate. With our movie, we have all of these fantastic hydraulic camera rigs and things, so we can push the camera up into the action, and follow the actors up into the set. When the corridor is rotating, the camera is actually clamped to the floor, and is running along a track that goes with the set, so it dollies back and forth, and it produces this fantastic dynamic look. Then what we do digitally, is we can fix the backgrounds, where the wires can be seen, and we can add little gags like, you know stuff coming out of the hotel trolley, and stuff floating around. Little drops of blood coming off of Ken Watanabe’s mouth and things like that. Which then helps confuse you as to which way is up, which way is down.

Ultimately, the core of it, is this, again, shooting it for real, this reserved reality. Then we make our visual effects fit in with the style of everything else that’s been done, rather than imposing something else upon it. The Special Effects and the Stunt Department did a fantastic job, Tom Struthers’ wirework was amazing, and Joseph Gordon-Levitt was incredible. He trained really hard for that; he worked out intensively with the Stunt crew for about eight weeks, and pretty much everything you see that was supposed to be Arthur, Jo’s character, that’s actually Jo, he did all of his own stunts. The Stunt crew made him a t-shirt: ‘I do all my own stunts’, because it was true.