By any account, John Krasinski’s A Quiet Place was a strong success. Made for $17 million, the horror film about a world taken over by sound-sensitive monsters went on to gross more than $330 million worldwide, earning significant critical accolades along the way. The film was so successful that it started a round of talk about its chances of Academy Awards, a seeming long shot made more plausible by the Academy’s new makeup and seeming growing interest in genre cinema. Emily Blunt’s performance as a mother trying to protect her children from the monsters — largely by keeping them completely silent — has come in for particular praise.

But the shoestring-budget effects are also worth noting, for the way they create a seamless, plausible reality. With the film now on Blu-ray and DVD, I sat down with special effects supervisor Mark Hawker to talk about his behind-the-scenes work on the film. His team managed the film’s practical effects, in coordination with Industrial Light & Magic’s Scott Farrar, who headed up the digital effects. The two men have worked on the same projects in the past, on films like Michael Bay’s Transformers: Age of Extinction, Steven Spielberg’s A.I. Artificial Intelligence, and Minority Report, while Hawker’s résumé also includes handling effects on several Pirates of the Caribbean movies, Terminator Genisys, A Wrinkle in Time, and a lot more.

This interview has been edited for clarity and brevity. Mild spoilers for A Quiet Place ahead.

How much of this movie was made with practical rather than digital effects?

There was actually quite a bit of practical, because of budgetary reasons. John was convinced he wanted to do as much as possible in-camera, so the actors had something to react to.

Did that involve building a physical version of the monsters for reference?

No, Scott did all the monster stuff, where you actually see the monster. What we did is like, as the monster’s attacking the pickup truck, we’re actually making the truck move around, we’re breaking the windows, doing all the stuff the creature would actually be doing to the environment. So the truck is bouncing and getting hit around, under Krasinski’s direction. And then Scott Farrar comes in with his team, and adds the monster in.

How did you handle coordinating with the SFX team, to get them what they wanted?

We kind of almost melt together, with what their needs are, what Krasinski’s needs are. I’ve worked with Scott in the past on Transformers. We look over the scene together to see what it requires, and he likes me to do as much practical as I can, especially if we have as much time as we did here. And then he comes in and cleans it up.

There was a lot of last-minute redesign on the monster on this film. Did that affect the practical side?

The budget on the movie was really low, so we had to come up with new ways of doing things technically. It was a lot of old-school effects for us. The creature change didn’t affect us — when we were down in the house basement, when Emily [Blunt] is there with the shotgun, shooting at the creature, and all the stuff in the room is flying around, that’s us doing that practically. But the shape of the monster, the size of the monster, that relatively stayed the same throughout. Its visual details didn’t matter to what we were doing.

I said we were finding new ways to do things, but I should correct that — it was more like going back to before digital effects. Old school. I had Eric Rylander on my set all the time, and he’s been in the business for 40-something years. There’s a lot of wire-work, monofilament work. We’re pulling objects over, making things float in the air with wires, instead of having visual effects do it.

What was your most complicated effect?

The corn [for the scene where the kids are in the corn silo]. We spent a lot of time researching and testing, and testing, and testing, because we had to come up with something safe for the kids. We had to use real corn because of the closeups on it. They fall into the corn, they sink into it, they go under, they’re moving around in the corn, so the safety rig we had to build for them was pretty complicated. It took four people to help operate it. That was the biggest challenge — keeping it safe and making it look good. But it came out really believable in the movie. In that whole sequence, there’s hardly any visual effects.

We built this rig — it’s like a latex balloon membrane, and it’s got a hole in it that the kids poke through. And then we have the corn lying on top of that. The latex itself isn’t strong enough to support all the corn — there’s about 12 inches of corn on top of it, and it’s very heavy. So there was a floating rig that could support all the corn, with a hole in it that the kids would go through, and the latex was like a gasket to keep the corn from falling through the rig. I’ve done quicksand rigs for actors, and this was similar, but the material we use on those can be really light. We originally said, “Okay, let’s do this our traditional way.” We tested the latex membrane alone, but the corn was so heavy, it weighed down the membrane and tore it. So we had to build supports underneath it, and it was very complicated.

Was the movie’s reliance on practical effects solely for budgetary reasons? Does John have any particular love of practical effects?

I think the mindset was to do as much practical as we could, and then if Scott needed to come in and tweak — sometimes our practical effects, I hate to say it, are just a reference for him to do it digitally, and what we did got completely replaced. Sometimes John just wanted to see it. Like with the nail going into Emily’s foot, we went back to the old-school way of having a retractable nail, so when Emily steps on it, it sinks into the wood. And then when she lifts her foot, it pops back out of the stair. I know Scott helped us out a little on the final effect there, but it started with an old-school trick nail.

In another case… when the kids are on top of the silo, and the boy falls in, we had rigged doors for that, so that on cue, we could trip them and drop a stunt person into the hole. There was a lot of fire on set, and they had to be particularly controlled, especially with the kids around it. We had to be really concerned and protective with things like the signal fire. When the safe room in the basement floods, we had to build a set that could actually hold water, and control the height and temperature of the water control, and keep it flowing and filtered and clean. People see that sequence and think, “Oh, they flooded a basement,” but no, everything had to be built to design.

That was another cost-saving thing we did. Usually, when you have a set with water in it, you build a large tank, larger than the set, and then build a set inside it, and flood it that way. But we didn’t have the space or the money for that, so we actually incorporated the walls of the set as the walls of the tank. And then the art department dressed them, painted them, or put stone over our walls that held the water. We filled the water with food additives to darken it, because that’s safe for people, and then talking to the set-dressing team, we picked paint and varnishes for the walls that wouldn’t leach out into the water.

So it was an effort with several other departments. And then the filtration system was just like what you’d have on a pool. We had to pipe everything outside the set, because we couldn’t have any noise inside, and we filtered it that way. And it had a little bit of chlorine in it, just to keep it clean.

What’s John Krasinski’s working method like?

He’s very passionate. It was like this project was his baby, which I loved. I was finishing up another movie when I started this one, but I couldn’t turn it down when John started talking about how much the movie meant to him. It was very addictive, him talking about the film and how he wanted to do it. So he’s great. I’d work with him anytime. He knows what he wants, and if you come to him with an idea or a thought, you can talk to him about it. He sometimes grabs hold of it — he’s easy to work with that way. It’s definitely a team effort with him.

Was there anything he wanted in this film that just couldn’t work out within the budget?

Originally, the silo sequence was much bigger, but there was no way to shoot it, the way it was storyboarded. I think the way it came out in the movie was much more precise and to the point, and I think it worked out really well the way it came out. It was just the practicality of getting into the silo with the cameras, and staying safe with the kids. In the storyboard, the creature goes through the side of the silo, and the corn dumps out, and the kids are dumped out. It just wasn’t practical to get the cameras in those positions. It’s just, it wasn’t practical. If you had a bigger budget and more time, you might have been able to get those shots, but with the time constraints we had… But I like what we got. It took away a lot of the fluffy stuff, and just kept the meat of the sequence.