Steven Soderbergh shot his thriller Unsane entirely on an iPhone 7 Plus. After the film’s premiere at Berlinale, the director revealed some of his tips and tricks behind how to shoot a movie using only a smartphone.

Unsane was shot in under two weeks and has received generally favorable reviews from critics and moviegoers alike. The movie follows Sawyer Valentini, played by Claire Foy, who relocates to Philadelphia to escape a stalker that has been following her for the past two years.

Once there, she tries to adjust to her new life but a series of unfortunate events end up with her being admitted to a psychiatric ward, held against her will. There, haunted by her stalker, she struggles with what is real and what isn’t.

Talking to Dazed, Soderbergh outlined how it was possible to create a movie with just an iPhone. Below are the best excerpts from the interview.

On sticking with the tried and tested and then pushing it to its limits

It was always going to be an iPhone that I shot with, because that’s what I had and that’s what I was familiar with. I suppose a more rigorous person would have tested everything that’s out there, but I knew what I could get out of my iPhone, and that was enough for me. That said, I intended to push it: I was going to put this thing through its paces and really challenge what the sensor was able to do.

On using what the iPhone can’t do to your advantage

Because sometimes you think something is a problem, but when you embrace it and double down on it, it turns out to be a really interesting anomaly that you can take advantage of.

On what gear you’ll need

Although we shot on an iPhone, we still all had the typical things that you would usually have on a movie – tripods, panheads, a handheld stabilisation device – but smaller versions of them. We used really small slates too! We had three phones in total. And that turned out to be more than enough: we never had technical problems; we never lost any footage or had any dropouts – they all worked perfectly. The fanciest piece of gear we employed was the drone for the shots of the hospital.

On taking risks

I was most worried about shooting the sequence in the woods at night because I’d made a very conscious decision to go for this very stylised day-from-night look. If it didn’t work I was kind of screwed. A traditional movie would have lined up a bank of 18Ks (lamps for night time exterior filming) to light that forest up like crazy in order to shoot that sequence, but low-budget movies can’t do that; they have to figure out another way. It was about halfway through shooting it that I thought, ‘No, I think this will be cool.’ I really like the surreal, dream-like quality it has. That whole sequence was scary to make but in a good way: there should always be something that scares you when you’re making a movie.

Check out the rest of the interview and Soderbergh’s tips here.

Next, check out why Tommy Wiseau is the Joker we need but don’t deserve.

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