First broadcast in 1963, Doctor Who is one of the UK’s longest-running television shows. Its longevity is due in part to the unique ability of its hero – a Time Lord from the planet Gallifrey – to regenerate his physical form, thus enabling successive actors to inherit the iconic role as the decades roll past.

With each new storyline, the Doctor’s dimension-hopping ship – known as the TARDIS – might be propelled to the farthest reaches of the universe, or into the darkest depths of time. Upon arrival, the Doctor and his companions are apt to encounter anything from a strange alien race to a famous character from Earth’s history … not to mention the inevitable army of monsters bent on mayhem.

Little wonder, then, that the show relies heavily on its special effects.

After its long initial run, Doctor Who was dropped by the BBC in 1989, and subsequently relaunched in 2005 by producers Russell T. Davies and Julie Gardner. Now under the auspices of showrunner Steven Moffat, Doctor Who has benefited from considerable continuity in terms of both visual and practical effects, with key contributors maintaining their presence throughout its current run. Practical effects are the province of Millennium FX, based just outside Chesham, Buckinghamshire, while visual effects are delivered by London-based Milk VFX, and the BBC Cymru Wales Post Production and Graphic Design visual effects team. Miniature effects are by The Model Unit in Ealing, with special effects by Real SFX.

“Before Neill Gorton and I became co-partners at Millennium FX, I had worked as a freelancer for Neill on shows including Saving Private Ryan,” recalled Millennium FX managing director Rob Mayor. “When the BBC commissioned Neill to do the work on the Doctor Who reboot, I was contacted to supervise the workshop builds and filming on alternate episodes – the first job being to create the alien Slitheen. One thing led to another, and I ended being the prosthetics supervisor, and subsequently co-designer on all the episodes since.”

“I was there when we brought Doctor Who back in 2005,” said Milk VFX CEO Will Cohen, formerly of Mill TV. “So I’ve been involved with the show since it came back nearly ten years ago. We opened Milk VFX in June 2013, beginning our continued involvement in Doctor Who with the 50th anniversary special — The Day of the Doctor — closely followed by the 2013 Christmas special, which was the last episode with Matt Smith. We pitched again about a year ago to do the new series with Peter Capaldi.”

A National Institution

With its long history and devoted fanbase, Doctor Who is more than just a TV show — it is a UK national institution which, in recent years, has become a global brand. The show’s long heritage is frequently honoured in new scripts as the latest incarnation of the Doctor confronts old enemies first seen in episodes now decades old.

“Having grown up with the show, we are extremely respectful of what has gone before,” said Mayor. “When a classic monster returns we usually get a heads up before the series goes into production so we can spend as much time as possible on design work. A lot of the original creations were amazing for their time but perhaps wouldn’t translate so well into modern television. So we are very careful to reference the feelings we got from seeing these creations as younger viewers. We incorporate them into the design, whilst also updating the look and taking advantage of modern materials.”

One group of monsters reimagined for the Doctor Who reboot was the Silurians — subterranean lizard-people who in their original 1970s incarnation sported trinocular vision. The new design — which debuted in 2010 — is more human in appearance. “The three-eyed design would have required animatronics,” Mayor explained. “As there were multiple different characters within the show, that would have been hugely cost-prohibitive. More importantly, the script was very heavy on emotive Silurian dialogue, which we felt would be better served through the use of thin facial prosthetics.”

For the 2006 episode Rise of the Cybermen, Mayor and his team reintroduced the classic cyborgs to a new generation of viewers. “The Cyberman suits were described in the script as big hulking stomping machines, so we echoed this in the design and build. In the later Cyberman episode Nightmare in Silver, they were silent, stealthy ninja-type characters, so we made them sleeker and more agile.”

The Cyberman suits were sculpted using a combination of old and new techniques. “From the approved concept, the suit was roughed out in clay over a form taken from one of our performers,” Mayor revealed. “This meant we could accurately see where areas of the sculpt might interfere with the movement of the person underneath. From here, we cleaned up the form on one side of the sculpt, scanned it and flipped it in the computer. We could then output the suit in sections, each of which we could detail, mould and finish.”

The Rise of the Cybermen suits were fabricated using a cold casting process. “We mixed aluminium powder with the fibreglass and cast it into the hard elements of the suits,” Mayor elaborated. “The result when buffed was a suit more lightweight than metal, but with exactly the same surface finish. They looked amazing on camera, but the downside was that the suits were quite heavy. We knew this wouldn’t work for Nightmare in Silver, so we went back to the drawing board to make suits that were lighter and more resistant to scrapes and bumps. The outer suit elements were cast and painted in urethane, while the undersuit was cast in a more flexible foam latex and painted with the same flexible chrome paint that the outer shells were finished in.”

Even more notorious than the Cybermen are the Daleks. “The episode called Dalek is one of my favourite episodes of the new era,” commented Cohen, “because it made the Daleks threatening and scary, and we got to see inside them for the first time. That’s the interesting thing about Doctor Who. Is it essential to have continuity from what came before? Yes, but also let’s not to be afraid to try new things or tweak old ones.”

The latest episode to feature the Doctor’s ultimate nemesis is Into The Dalek, which begins with an expansive running space battle before it segues to the claustrophobic interior of one of the metal-clad aliens. “The battle was a chance for us at Milk to doff our caps to Battlestar Galactica, which we love,” Cohen enthused. “This episode gave us a chance to do a full-CG space battle that sets the scene for the internal drama that follows.”

For scenes set inside the Dalek, Milk created a number of CG environments. “We were kind of given carte blanche with the Dalek interior, because nobody knows what it looks like,” said Milk visual effects supervisor Murray Barber. “We did a lot of set extensions looking down corridors to see Dalek roundels on the walls. There was a very early production meeting where it was said — by Steven Moffat, I think — “If it looks like we shot it in a factory in Wales, we’re lost.”

Taking a Deep Breath

In Deep Breath – the first episode of the current series – the Doctor and his companion Clara are whisked back to Victorian London, where they encounter the Half-Face Man: a sinister cyborg with a hollowed-out clockwork visage. Because historical London environments have featured on the show previously, Milk VFX were able to repurpose existing CG assets as a starting point for the spectacular opening sequence, which sees the capital menaced by a 200-foot-tall Tyrannosaurus Rex.

“We reused a lot of assets,” Barber confirmed. “Because we got so close to the Houses of Parliament, we rebuilt Big Ben, but most of it is stuff we’ve used before. Each time we use it we update the model, changing some of the textures and adding more buildings. It’s a progression, but we do have quite an extensive library of elements now.”

The London model was also adjusted for historical accuracy. “It all depends when in Victorian London you are,” Cohen commented. “You have to get the year right. For example, right up to the end of the 19th century, certain bridges didn’t exist over the Thames, or were being constructed. We had some nice photos from 1883, when the buildings on the south bank of the Thames looking west were all very uniform and mansion-like. Once we’d built one, we had the dozen or so we knew we needed to see.”

“When you’re doing a flyover shot, it’s never going to be street-perfect,” Barber noted. “You try and make it as accurate as possible. Our main matte painter, Simon Wicker, is a great advocate of Cinema4D — our huge library is mainly built in it.”

Cohen added: “For The Day of the Doctor, which was stereoscopic 3D with big camera moves, and which had a cinema release, we took a lot of the environments into Maya. So we have the two pieces of software working in tandem – they’re getting more and more conjoined in the pipeline.”

A particular challenge was selling the scale of the gigantic dinosaur that roams the capital’s fog-shrouded streets. “Maybe Steven Moffat had seen Godzilla over the summer, I’m not sure,” Cohen mused. “We designed a new T-Rex and made it big, and it was approved pretty quickly. But it wasn’t just a case of scaling it up. We had to get the textures right, and the rig, skeleton and muscle system are all new. They’re an evolution of what we’ve done on shows like Primeval.”

The Half-Face Man was realised through a combination of prosthetics and visual effects. “We all quickly realised that he was going to be a mix of CG and practical prosthetics,” said Mayor. “Obviously, to see right inside the head, we couldn’t just utilise prosthetics on the actor — who was the brilliant Peter Ferdinando — so we created a textured foam latex version of the metal framework. Over the top and around the edge of this we applied a silicone appliance to give the appearance of ripped skin. Milk then used the framework as a rough starting point for the internal elements. These elements were sculpted by Reza Karim.”

“We looked at movies to find an example of a similar effect,” Cohen affirmed, “and came up with the face replacement work on Two-Face/Harvey Dent in The Dark Knight. They spent hours tracking Aaron Eckhart as he moved within 3D space to get everything to lock on properly. That amount of work is often impossible on a TV show.” The knowledge that Deep Breath would have a theatrical release added to the pressure. “One pixel out on a television might not be noticeable,” Cohen observed, “but one pixel out in the cinema, and the whole effect falls apart.”

To mitigate the risk, minor modifications were made to the design. “Originally the jaw and the hole in his head were a bit lower, exposing more muscle and sinew on his jawbone,” Cohen recalled. “Murray suggested raising the skinline tear a little to make it more doable, without spoiling the overall chilling effect.”

As well as the prosthetic elements, Millennium also built a puppet version of the Half-Face Man’s head and shoulders, for scenes set in the villain’s lair beneath a London restaurant. “We started with a fibreglass core taken from Peter Ferdinando’s head cast,” explained Mayor. “Animatronics artists Tim Rose, Nico Zarcone and Gerard Moore turned the entire rig and the internal clockwork mechanics around in a few days. Over the fibreglass core was a silicone skin of Peter complete with hand punched eyebrows. We also built a prop arm gun, designed by Brian Coldrick and realised by Pete Fielding, that was worn by the actor on set. Additional fire elements to the arm were added in post. So some elements were practical, some VFX and some a mix of both. Milk, who are as brilliant as ever, seamlessly blended both practical and CG to create a truly believable effect.”

“We photoscanned the Millennium puppet as the basis for making our 3D model,” said Cohen. “The original plan was to use CG only in shots where he was travelling across the room, or moving his head around in a way where you needed to get that parallax. But if he was going to sit in the chair and not do very much, we thought we would get away with compositing and split-screening the puppet. In the end, I think we used the puppet in about four shots, and we did 87 digitally.”

Tracking markers on Ferdinando’s face and hat allowed Milk artists to line up their CG model with the prosthetic-enhanced face of the actor. The mechanically-operated eye was animated by hand to match Ferdinando’s real eye. “It’s just a very lovely visual concept, to be able to see through to the other side of him,” Cohen observed.

Men In Suits

Time Heist, one of the later episodes in the current series, features an alien character called “The Teller”, which Rob Mayor describes as “a good ol’ fashioned foam latex full monster suit”.

The Teller has telepathic powers, the use of which is signalled by the bringing together of its highly mobile eye stalks. “In the very first production meeting, Neill Gorton came up with the idea of the alien being able to draw its eyes together, like when you put your hands together to meditate,” Mayor explained. “From there, two small-scale maquettes were sculpted by artist Gary Pollard, one with its eye stalks down, and one with them in ‘telepathic’ mode. After approval, the full-size version of the head, hands and feet were realised by one of the series supervisors Dave Bonneywell.”

The movement of the eye stalks demanded a complex animatronic solution. “The beautiful mechanics for the Teller were turned around in a few weeks by animatronic designer Adrian Parish, assisted by Matt MacMurray,” said Mayor. “Because most of the movement was coming from the mouth and eyes, Adrian and Dave came up with the nice twist of having the eyes not only open and close, but also retract — just because it would be a cool extra bit of detail.

“All the builds for Doctor Who are turned around within a few weeks, but it’s this extra effort that’s indicative of the crew’s love for the work. The head was run in foam latex with a soft silicone membrane cast over the brain, on the top of the head. The paint scheme was designed by Dave and our full-time designer Chris Goodman. Performer Ross Mullan along with Dave and Adrian then bought the Teller to life on the shoot in Cardiff.”

The “full monster suit” has been a staple of Doctor Who since the show’s inception in 1963. “Doctor Who was always a man in a suit, and to be honest there is no reason to drift away from that,” Mayor contended. “I’m a huge fan of CG and wholly respectful of the skills utilised within it — and yes there are instances where practical effects are just not a viable option — but I still feel a lot of audiences make more of an emotional attachment to a creature knowing they are actually standing right next it. As a bonus, a lot of the Doctor Who fanbase centres around conventions, exhibitions and live shows. To see the looks on people’s faces as the Judoon, Cybermen, Silurians and Weeping Angels appear on stage and interact with them is priceless.”

Milk added CG ‘telepathic waves’ to shots in which the Teller sucks its victims’ brains dry. “At one stage we were going to do some digital stuff with the eye stalks, but that went away, for all the right reasons,” Cohen recalled. “Millennium did brilliant work on the Teller, a really successful creature.” Digital techniques were used to illustrate the aftermath of the Teller’s disturbing interventions: lobotomised victims with caved-in skulls. “The crushed heads were based on actual photographs of people who have part of their skull missing,” said Barber. “What happens is the skull is gone and part of the skin just sags in.”

Milk also created environments for the Bank of Karabraxos, including a master shot of the main banking hall. “That was a massive matte painting,” Barber explained. “The set was about a quarter of the size of the finished thing. We took the live-action plate and doubled it over twice; when the camera tilted up or panned down, that was all CG.”

Television Timescales

The Doctor might have a time machine at his disposal, but all the artists working on Doctor Who are locked into the tight deadlines characteristic of television production. “We normally start prep on a two-episode block six weeks before the shoot,” Cohen revealed. “We have a meeting with both scripts — or early versions of them — then quickly do the designs for any CG assets that are new, and get those approved. That might go through a couple of iterations. We then make the assets, and rig and prep them to be production-ready. We might have to produce some previs for the shoot, or postvis for the edit. And then we set about making it. Occasionally, people get the odd surprise if something isn’t how they visualised it. But there’s no real time to go back. We try to spring as few surprises as possible for the production team by approving greyscale animation as we go along.”

The team at Millennium follow a similar approval procedure — against the same relentless ticking clock. “With the new creatures, we start by using any descriptions within the script,” commented Mayor. “We then look at what action it needs to perform and if there are any specific requirements within the story. Once we are happy with our initial sketches — 99% of the design work is done internally — we send them off to the producers and director for their input and approval. If there’s feedback, we make adjustments until everyone is happy. We’ve been fortunate enough to work on the show for so long now, and are so tuned to its ethos, that more often than not we hit the nail on the head. We know how to create a balance between design, functionality, timescales and — I hate to say — budgets. Which when working on a fast-paced, high-production-value television show is an essential skill.”

The clock hands continue to spin throughout the production process. “On set, we do HDRI, silver ball and grey ball references, and photoscan all the sets,” said Barber. “The only problem is that the sets get struck so quickly. You take a break and go back and the set’s gone! You’ve got to be quick. Other than that, we use exactly the same techniques as on a feature film.”

The quality of the effects in shows like Doctor Who proves that the line between television and cinematic visual effects is becoming increasingly blurred. “The convergence of technology means that film and TV people are now all mixed up as artists,” Cohen observed. “One week they’re working on a massive feature, the next week they’re working on Doctor Who, using the same kit, the same technology, the same techniques. And now with television — with the proper planning, timing, budget and experience — you are able to get close to a cinematic standard. It’s a rich time for television.”

Who’s Your Doctor?

Every fan of Doctor Who has an actor they consider to be “their Doctor” — the particular version of the character they grew up watching.

“For me as a child, it was Tom Baker who made the biggest impression,” Mayor remembered. “He was my first introduction to the world of Doctor Who. I used to sneak downstairs in the evening and peek at the TV through the crack in the front room door.”

The Milk VFX team also remembers the Tom Baker era with fondness. “I caught the tail end of Jon Pertwee,” said Barber, “but I suppose Tom Baker was really my Doctor. Although I have to say I liked Matt Smith.” Cohen added. “I remember hiding behind a brown sofa in our 1970s living room watching Jon Pertwee. The show freaked me out.”

Are you a Doctor Who fan? What’s your favourite monster or special effect from the show, and why? And which of the many actors who have played the legendary Time Lord is YOUR Doctor?

Special thanks to Edward Russell, Jenny Burbage and Dave Bonneywell. Photographs copyright © 2014 Doctor Who / BBC One and courtesy of Millennium FX and Milk VFX. This article has been edited to include BBC Cymru Wales, The Model Unit and Real SFX.