Christopher Nolan’s “Interstellar” is state of the art, yet old-fashioned: He filmed in L.A. as much as possible, prefers physical sets to greenscreen and watches the rushes in 35mm. Audiences like the results: The film has passed $620 million so far at the global box office. Here, Nolan talked with Variety about his unique process with production designer Nathan Crowley, working with longtime collaborators, and the “weird” surprise he gave Hans Zimmer.

Production design, Nathan Crowley

“He’s one of my most closest and inspiring creative collaborators. Often when I’m finishing a script, before we have anybody on board, he’ll come on — and in my garage, we will start throwing ideas around, doing sketches, building models; we noodle around, just as a pure fun time. There are no mouths to feed at that point, there are no big departments needing to know what to build, how much it will cost and so forth. So for six to eight weeks, we try to mess around with the pure creative side. Tesseract, that space inside the black hole, that was one of the first things we started messing around with, to build models with. That was an incredibly valuable period because none of the technical or financial difficulties creep into that process. It’s just the two of us messing around, and a lot of the finished film comes out of those conversations. It’s a unique process. I think we developed it with ‘Batman Begins.’ When we showed the script to the studio, I wanted to show them what the look would be. It felt important to get that across. So while we were working on script, I had Nathan working, to show them what the Batmobile would be. I think he really enjoyed the lack of pressure, being alone as an artist, without draftsmen needing to be fed every day with new things to build. It’s a process of expansion of vision, if you like, always pushing things further and further. As soon as people come on, you have to get practical. And he’s great at that part too, but it’s joyful to have that bit at the beginning where there are no rules.”

Music, Hans Zimmer

“His score is really special. It’s some of his finest work and most personal, which is what I love about it. I called Hans before I started working on the script. I said, ‘I won’t tell you anything about my next film, but you have to give me one day off from whatever you’re working on.’ I said, ‘I’m going to give a letter that will tell you a fable, the emotional heart of the movie. Give me one day, then play at the end of the day. And you write whatever you feel.’ Hans loves a weird challenge. He played me a tune that was exactly right. And then I said, ‘By the way, it’s an enormous science-fiction film,’ which he was pretty surprised about. But that was the whole point. We turn the process inside out. On an action film, when you build big machinery of an action score, it becomes difficult to get back to the heart of the movie. I said, ‘Why don’t we grow it the other way around; let’s start with the seed of emotions.’ He built the score from that initial inspiration. The core relationships between father and children is in everything in his score, even when it’s supporting the action. He’s gone massive with some intimate moments and tiny with some of the largest moments. It’s the contrast in scales that spoke to me about what the film is trying to do between intimate emotions and the cosmic scale.”

Cinematography, Hoyte Van Hoytema

“Clearly people appreciate his work, but he had enormous challenges, particularly with the Imax format, with its enormous cameras. There were technical challenges to shoot, for example, the space ship interiors. I insisted on building fully enclosed interiors. You had to crouch down and get through the hatch, like astronauts do. Hoyte found ways to jam that camera behind the console. And we didn’t use any greenscreen; creatively, that was a huge inspiration to Hoyte, but technically it meant he had to shoot wide open, on this large film format, to get enough brightness out of the projected images outside the windows, and we had nowhere to conceal lights. The look that he was able to achieve, with those restrictions, was extraordinary — for anyone who knows the art of cinematography, and with the technical restrictions imposed on us — (with a laugh) I suppose I imposed them! — but he was up to the challenge.”

Editing, Lee Smith

“He tends not to show me things while we’re shooting. I’ll take a look if I need to. He assembles the whole way through, lets me know if there are problems. Then we start the edit from scratch, a scene at a time. He’s the fastest editor I’ve ever seen. That gives me so many options. He gives me 10 different things in the time it would take most people to do one. It’s invigorating. I ask him not to cut with music, so we’re ruthless on pacing and how imagery tells the story. I don’t cut with pre-vis, so there’s nothing for him to do until we start shooting. He and John Lee, his first assistant, are a great team. Lee comes on fairly late in prep usually. He’ll have read the script many months before, just so I can get his thoughts about it. We still run dailies on 35mm, the whole team watches, in continuous collaboration.

Sound design, Richard King; sound re-recording mixers, Gary Rizzer and Gary Landecker

“They mixed in a unique way and pushed boundaries, particularly with the approach to space and the lack of sound. This was not doing the traditional science-fiction sound; We wanted an unconventional sound. There’s a grit to it, a reality, without the usual gloss. They took stuff we recorded on set, with its funny creaks and groans and they built tracks out of that. So there are extraneous hums and bells and whistles. It was a documentary style, which complemented Hoyt’s work. We have robots, for example, and rather than having this multilayered pistons and internal servers, when Charles walks around, it’s file cabinet doors opening and closing.”

Visual effects, Paul Franklin

The visual effects supervisor was Paul Franklin, who has been a very close collaborator on several films. He is also fascinated with science. I put him in touch with Kip Thorne, an astrophysicist who is our exec producer, so that the black hole, the wormhole, can be drawn from real science. What you see is the most accurate depiction of a black hole possible today; they found things they will publish papers on. On the spaceship side, he brought in a Los Angeles company, New Deal, to do miniatures. He also collaborated with Scott Fisher, who’s the ‘floor guy.’ They had a close collaboration that is unusual these days. There are no green screens. Everything in the spaceships is shot in camera. So Paul and Scott had to collaborate to create the environment for actors: the forces they were encountering, the atmosphere, lighting changing, clouds; they had an incredibly close working relationship. They were also able to collaborate in a way that I don’t think had been done before, an unusual mixture of miniatures and full-size elements. It was a special collaboration between special effects and visual effects, which is where I like to live.