Chris Nolan and the Interstellar team talk about the down-to-earth solutions for their out-of-this-world film.

Sunday night, while steam engines and early spacecraft stood on silent display on the floors below, the London Science Museum’s IMAX cinema was packed for a screening of Christopher Nolan’s breathtaking sci-fi adventure, Interstellar. A post-screening Q&A featuring Nolan, the film’s editor Lee Smith, director of photography Hoyte van Hoytema, and VFX supervisor Paul Franklin.

Nolan has been a steadfast advocate for the superiority of shooting film over digital, and seeing the stunning result you understands why. But beyond the adherence to shooting film, it became apparent in the Q&A that throughout the entire production, the organic intuitive option always took precedence over engineered digital certainty.

“The spacecraft was more a simulator, than a set,” said Nolan. The actors were enveloped in the reality of the film. With a cockpit complete with vibrating chairs, maneuvered by crew who rocked the set on gimbals to simulate motion.”

Whenever possible, Nolan shunned CGI, mostly because it was the best practice for creating the film he wanted. There are over 180 in-camera projection shots in the film.

“People regard rear projection as an old technology,” said DP Hoyte Van Hoytema. “But there are so many things you can do with it now onset. You can rescale, change brightness, twist it, change direction. New tools have given it a whole new life.”

Employing as many onset effects as possible also helped the visual effects bottom line. “Rear projection pushed us to get everything done up front, rather than doing it all in post, as usually happens,” said VFX head Paul Franklin.

He pointed out how the IMAX format pushed artists to engage with the work in a more active way. “There is no digital display system that will allow you to look at the full IMAX image all at once, so there was a lot of guess work involved. You had to get a feel of it.”

The whole approach of the film seems embodied in the key character of the robot TARS, voiced and puppeted by American clowning genius Bill Irwin. TARS is a kind of robot embodiment of IMAX – an ultra-retro rectangular design, displaying his data on a couple eye-level screens. After years of terminators and transformers, you’re almost embarrassed to see such a primitive robot design, but as the story unfolds, so does TARS, like IMAX continuously surprising and fascinating with its adaptability, power, and warmth.

Editor Lee Smith said that the heavily processed gyro sound effects originally designed for TARS’ movements just didn’t work. Unable to find a digital solution, Nolan suggested the team try the noise of a file cabinet. The resulting, very mundane crashing noise ends up bringing the future technology down to earth and connects us to the character’s reality.

Interstellar also uses the silence of space in stunning – Kubrickian – ways. Nolan pointed out “Every time you cut to the silence, it reminds you that human beings aren’t supposed to be there.”

But where I sat in the very back of the cinema, those silences weren’t perfectly silent. I could, in the projection booth behind me, the faint whirring of the IMAX projector – a comforting sound, like having TARS along doing his bit to save all that was good about yesterday’s earth.