Visual effects (VFX) play a crucial role in the modern movie industry. Daniel Radcliffe talks to friend and physicist Jess Wade about what it’s like as an actor to work with this kind of technology
Jess Wade: You have been in a bunch of films that use VFX in the most progressive and creative ways. What was it like starting your acting career with the extraordinary VFX in the Harry Potter films [2001–2011]?
Daniel Radcliffe: For some of the experienced actors on Potter, it was their first time working with VFX on that kind of scale. It was different for us kids. Telling us that “the dragon is this tennis ball on the end of the stick” is a little different from giving an older actor that instruction – we’d never known anything different. And we were all kids, so using our imagination was something that we were doing a lot anyway.
JW: Has VFX changed how you act?
DR: I don’t think so – it’s always been a big part of my career. I enjoy the challenge of it. I think I’m weirdly good at following numbered cues now. I remember when they shot all the audience reactions during the Tri-Wizard Tournament [in the fourth film, Harry Potter and the Goblet of Fire (2005)], and there would basically be a bunch of the cast and background artists on a big stand – sometimes on a green screen, depending on what the backdrop was. Assistant directors would hang big numbers around the studio and just say, for example, “1” so everyone would turn to the same eye line at the same time.
JW: The Harry Potter films ended eight years ago, and you’ve done some really exciting things with VFX since then. Has it changed a lot?
DR: Potter came at a time when people were leaning heavily toward visual effects and away from “practical” make-up or special effects. Even though, of course, we had plenty of them too. In the last couple of years, we’ve reached a nice balance – where big franchises like Star Wars and Mad Max use a lot of practical stuff in creature effects and stunt work. People see the value of having practical, on-set effects, but VFX are so good. It can also make stunt work safer because you don’t have to put a human being through what you can get VFX to do.
But certainly, VFX is improving at an extraordinary rate. If you were to look at the difference between the first and last Potter films [in 2001 and 2011] – they get exponentially better over time.
JW: How does working with all that VFX compare to stage acting?
DR: I think that’s the joy of my job – I’ll do some films where there’s almost no VFX whatsoever, then I’ll do films like Swiss Army Man  where it’s a crazy mix of VFX and old-school practical stuff such as camera tricks. There was one scene in that film where my character gets punched in the mouth, then swallows the hand that punches him… and punches himself in the stomach to make the hand that’s in his mouth get forced back out. I wondered “how are we going to do that?”. There was no VFX involved – it was entirely clever camera angles and a bit of make-up on the arm to make it look like it was covered in spit. It’s wonderful to be able to flit between those things – the very low-fi and the highly sophisticated ways of solving problems on film.
JW: Do you ever get involved with VFX? Do you go and see what they’re doing?
DR: The closest you get on set is when the film’s big enough to do previs [previsualization] sequences – like an animated storyboard that no-one else ever sees. For example, when there was a big quidditch sequence on Potter, they’d have that all mapped out on a visual storyboard first, and we’d try and stick to that when we filmed. But the majority of the time, the VFX is in post-production, when the actors aren’t around.
JW: But sometimes you go in to do that funny thing – what’s it called – ADR?
DR: Yeah, ADR – additional dialogue recording. At that point you might see some sequences with half-finished VFX – and that’s always cool; it’s always fun to see it in a primitive phase. For someone who is interested in how films get put together it’s kind of fascinating. In this rough cut of the film there will be shots like, if you did a driving sequence on a green screen, they’ll just show the shot on a green screen with a little caption saying “VFX needed”.
When films started using huge sets that were just entirely blue screen and VFX, I think actors were a bit whiney about it – there’s something about being on a bright blue or green screen that can drive you slightly insane. At first it was something to be remarked upon, but now it is so much part of the industry – I don’t think anyone sees it as a novel thing anymore.
JW: What’s your favourite example of VFX that you’ve worked with?
DR: That’s really hard. There are some amazing sequences in Potter – there is some really beautiful stuff. The Hall of Prophecy in [the fifth film, Harry Potter and the] Order of the Phoenix  was almost entirely green screen if I remember rightly.
And then in Horns , when my on-screen brother took some hallucinogenic drugs and had this really visual trip – that’s a really good mix of practical prosthetics, VFX and tricks the designers built into the sets.
There’s also the other side of VFX, which is less glamorous but even more useful. Like driving sequences – when you’re filming in a place where you can’t shut down roads, you have to do it on green screens. Then there’s patching up a prosthetic. Sometimes things look fantastic when they’ve been put on at 9 a.m., but when you’ve been wearing it for 10 or 11 hours, visual effects can be helpful for polishing up that stuff.
JW: What has been the most ridiculous thing that you had to work with?
DR: None of it feels too ridiculous at the time. The hippogriff [a magical creature that’s part eagle, part horse] in [the third film, Harry Potter and the] Prisoner of Azkaban  – the reality of the hippogriff and the flight of it was quite funny. If you imagine a limbless, headless bucking bronco…
JW: [descends into laughter] Like…a mechanical thing?
DR: Yeah, a mechanical bucking bronco on hydraulics. Just a grey torso with no texture, filmed on a blue screen and a green screen with a motion control camera.
JW: [can’t stop laughing] But you were all kids! I imagine when one 14-year-old starts laughing, everyone starts laughing.
DR: Sure, there would be an element of that. Thankfully, for the hippogriff sequence I was on my own at the start – so I’d got used to it. Of course, it also feels slightly strange when you mark it through for the first time if you’re acting alongside something like a tennis ball, but you get used to it.
JW: Is it weird to watch yourself after you’ve been VFX-d?
DR: It’s not weird so much as it is cool! It’s satisfying and really fascinating to see the finished product all put together, after having seen it at its most basic stages.
JW: Have you had experience with any cool VFX technologies?
DR: On Potter there was something called cyber-scanning. You’d stand in the middle of around 30 cameras and a computer would make a 3D map of you. And you know, as a kid, I had to be very still for a long time. They also had to keep doing it for every film because us kids were growing up.
JW: What did they use that for?
DR: If there’s a scene where you’re being thrown around in a crazy way – or you’re falling from a broom or something – and they didn’t want to do it with a stunt man. They use the cyber scan to recreate a digital version of you.
JW: It’s kind of cool but also intimidating. I think I’d hate to have 30 cameras pointing at me from all different angles.
DR: Yeah, for sure, it’s weird. You don’t just sit there either – you sometimes have to make expressions. There will be six or seven “first do a neutral face, then do smiling, then smiling with teeth, then surprised, then scared…” – so you have to make slightly caricatured versions of facial expressions. It’s one of the weirder parts of my job – but I enjoy all of those parts of my job!
JW: Does it feel like there’s a movement in the film industry to go back to more old-school techniques, away from VFX?
DR: Maybe a little bit. If you go to one of J J Abrams’ sets for the new Star Wars films there are lots of practical prosthetics, make-up effects and creatures – it’s really cool. It’s one of the things people love about the films that he has made.
The directors of Swiss Army Man, Daniel Kwan and Daniel Scheinert, love doing stuff practically. There are sequences in the film where we’re attacked by a bear, and there is no safe or practical way of doing that really, and we didn’t have the money that The Revenant  had to do a bear attack. But Dan Kwan has a VFX/animation background and knew how to film things to make the VFX easy – there are tricks.
People used to say they didn’t want movies to look like video games – but video games look incredible at this point in time, so it’s not really a valid criticism anyway anymore. I don’t think we’ll ever get to a point where we completely do away with human actors and have entirely VFX movies – though there is a place for those movies right now, and they’re awesome.
You see how people respond to films like Mad Max: Fury Road , which had a lot of practical stunts, the crazy cars – that was all real. But it was coupled with a tonne of VFX – removing wires, stunt harnesses. I think the industry has got to a point where we realize the value of both and find a compromise between the two.
JW: When you think about your career – of course you think about acting, but increasingly producing and directing – do you see yourself getting more involved with VFX?
DR: Depending on what level of VFX is in the film, VFX teams work very closely with the director. I think it’s really important to work with people you get on with and who understand the vision of the film. I cannot overstate how important that relationship is – the VFX team can really bail you out of stuff. On Guns Akimbo  there was a lot of VFX, and we had a very chill, cool VFX co-ordinator called Tony [Kock] – and whenever there was a problem on set we’d say, “Hey Tony, can you fix that?” and he’d be like, “Yeah, that’s fine.”
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JW: When you find someone like that do you not just want to ask them a tonne of questions about the technical parts of it?
DR: I do, but it’s like when I ask you about physics – I can only understand so much.
JW: Talking of physics, it’s not often we have a film star in Physics World. If you played a physicist who would you be?
DR: I will reverse the question: who would you cast me as?
JW: Paul Dirac would be great. Remember we read that great book about him [Graham Farmelo’s The Strangest Man]. But I want to know more about whether you like physics?
DR: I was always excited by space but there was way too much maths in it for me to ever feel truly at home. I’m interested in it now though – absolutely. You know I always watch science shows and listen to podcasts. I guess I’d say I’m an enthusiast but I’m not informed. Maybe I got it from my teachers at school and my tutors on set. Even though I wasn’t great, they got me interested. But I think pretty much across the board, every subject I didn’t think I was good at when I was at school, I’m fascinated by now. I’m fascinated by mathematics. I don’t understand anything about mathematics, but I love hearing people talk about it. It blows my mind.