How Stranger Things Season 4 Went Running Up That Hill With A Mix Of VFX And Real Sets

A lot of directors rely on the robust realism of digital effects to create their universes. The downside of constructing the set in post-production is that it requires the cast to interact primarily with green screens. The "Stranger Things 4" crew chose to use a hybrid of practical and digital effects instead, giving the actors something material to work with. This provides the hit Netflix series with a texture of authenticity.

"Stranger Things" is a nostalgic sci-fi horror series set in the '80s. It centers around a group of kids united in their love of Dungeons and Dragons. One day they stumble upon Eleven (Millie Bobby Brown), a girl with telekinetic powers who had recently escaped from a lab. When supernatural powers from a terrifying alternate dimension begin claiming victims, the kids must help Eleven fight to save the world from being overtaken by monsters.

In Season 4, a new villain is introduced — Vecna (Jamie Campbell Bower). He is the most human of all the monsters in the series, which in many ways makes him the biggest threat. He invades the minds of troubled teenagers, like Max (Sadie Sink), and accesses their darkest memories to torture them with hallucinations. He almost succeeds in killing Max when she accidentally lands herself inside his Mind Lair, but she makes a narrow escape in an epic battle scene.

The set was challenging for Sadie Sink

To create Vecna's terrifying and surreal landscape, series director and executive producer Shawn Levy chose to use a mix of constructed sets and CGI. "We always try to combine real art department constructed environments with these digital elements," Levy explains to Netflix. The director's reasoning behind this decision is twofold. "The more you practically build, the more you're helping the actor do their job, but you're also helping the audience with kind of an on-ramp to believability," Levy says.

Sadie Sink definitely agrees with Levy's first point. "It feels real, like the stakes are really high," the actress said of shooting her battle with Vecna in "Stranger Things 4." Vecna's Mind Lair "was not the easiest set to film on," she admits. "But I mean, it looks amazing." Some of the more challenging practical elements of the set included "how slippery the ground was, and how careful I had to walk on it," Sink recalls.

However, some of the digitally rendered set-pieces presented a challenge as well. For instance, Sink had to pretend she was being restricted by Vecna's vines, which were added in later by digital artists. "We wanted the vines themselves to almost echo the flesh monster from season 3," Levy explains. This texture was easier to mimic through computerized visuals than through practical effects.

The crew used less CGI than you might think

Some unexpected pieces of the set were constructed in real life. "One thing people assume wasn't real, but was, is that winding staircase. That was very much there," Levy reveals. This allowed the director to "frame the expanse of the Mind Lair," grounding the cinematography in reality. Another real piece of the set was the dead bodies, including Vecna's first victim of the season, Chrissy (Grace Van Dien). "We augmented the gauntness of the face and the hollowing out of the eyes," Levy explains, which means that the corpses were adjusted with digital effects. "But, again, those were real dummies mounted in the practical set, which gave Sadie something to react to."

Sink was probably grateful for the physical cue marker, but she didn't find Chrissy's corpse too scary in real life. "Chrissy's dead body didn't look as good as it looks in the finished product, but Vecna looks just as scary in real life as he does in the show," the actress admits. This is because Vecna is also comprised of "90-95%" prosthetics and makeup, according to artist Barrie Gower (via CinemaBlend). Since Vecna is "humanoid in his form," Gower explains, the series creators "were very keen to have somebody who had a very practical and on-set presence that could interact with the cast every day, rather than a character which is visual effects, somebody in a green screen suit."

By blending the digital with the practical, "Stranger Things" makes a completely fantastical universe feel true to life. The actors feel truly immersed in the world of the Upside Down, and in turn, so is the audience. Vecna and his lair are some of the most terrifying elements of the show because, through the thoughtful work of the cast and crew, they are extremely realistic.