The history of Steven Soderbergh is the history of making do. The steadfast indie director likes doing his movies his way, and when money poses an obstacle to his purity of vision, he’s always quick with an industry workaround. He wanted to make a 250-minute account of Che Guevara’s life to be spread across two films and shot entirely in the Spanish language, and since Hollywood wasn’t interested, he hawked his wares with French and Spanish distributors instead. The big studios refused to release Soderbergh’s Liberace biopic Behind the Candelabra unless he first recut it, so he bypassed US theaters entirely and found a welcome home at HBO. He managed to free himself from overseer shackles entirely by selling all the streaming and TV rights to Logan Lucky ahead of its release last year, using that capital to finance the film, and then divvying up the box office proceeds among his collaborators instead of suited investors.

His latest film, Unsane, shouldn’t have been such a tough sell. The ripped-from-the-headlines psycho-thriller traps unstable bank employee Sawyer Valentini (Claire Foy) in a mental care facility against her will, and to make matters worse, she’s pretty sure one of the orderlies is the man who has been relentlessly stalking her for years. But for whatever reason – perhaps because Soderbergh places his focus on the unsexy topic of the American healthcare-industrial complex’s myriad failings – he ended up working on a humble scale with a modest budget.

The most conspicuous sign that he’s playing minor-league ball is the R1 Pro from Shoulderpod, a rudimentary camera rig that uses an iPhone to shoot footage. Soderbergh has insisted, however, that he appreciates the crispness of the 4K video quality and that he does not see this as any manner of concession. “I think this is the future,” he told Indiewire. “Anyone going to see this movie without any idea of the backstory to the production will have no idea this was shot on the phone.” It’s the skill of a great artist to turn a limitation into a strength, and indeed, Soderbergh has harnessed the potential of the gizmo in your pocket to create a striking and affecting new visual dialect. Bad news, fellow laypeople: we no longer have any excuse for not having completed a feature film.

Don’t get it twisted, the iPhone’s no substitute for a 35mm camera; it’s its own thing, and all the better for it. For purists, the cinematic medium is synonymous with the warm, lived-in grain of the celluloid filmstrip. Digital video introduced a cleaner, more sanitized look that may have boasted a higher resolution, but still proved alienating to some traditional audiences. That unnatural feel has been a stumbling block to other productions, but here, that quality is precisely what makes the iPhone perfectly suited for Soderbergh’s purposes in this film. The iPhone flattens an image’s depth of focus without losing clarity, creating a disorienting effect in which something feels wrong even when the frame is all in order. At times, the amount of visual information that Soderbergh can force into the foreground is somewhat overwhelming, as the brain rushes to decide where the eyes should be drawn. How better to communicate the mental interiority of a woman losing her mind?

Soderbergh also capitalizes on the lightweight maneuverability of the iPhone for some exhilarating seat-of-his-pants cinematography in the film’s most arresting scene. Things aren’t looking so good for our gal Sawyer near the end of the second act, as her tormentor has trapped her in a padded solitary confinement room with no escape. When Sawyer and the demon that just won’t go away finally dive into the explosive conflict their film has been building towards, Soderbergh goes handheld to get visceral 360-degree coverage in a tiny, claustrophobic space. Cutting as few times as possible to preserve the tension, he conveys the feeling of having nowhere to run, as if the viewer had been imprisoned as well.

The iPhone is not a fully democratizing tool, instantly freeing the unknown auteurs-in-waiting from technical shackles; the film only works as well as it does because Soderbergh knows his stuff. (A lifelong fan of aggressive color-grading, Soderbergh also owes a lot of Unsane to a sophisticated post-production touch-up.) But every year, the gap between the capability of knowhow and the limits of capital gets a little smaller. This development has allowed for lots of amateurish dreck, but Soderbergh and director Sean Baker – who also employed the iPhone for 2015’s Tangerine, his outstanding predecessor to The Florida Project – help to set a higher standard. They’re forging a new film marketplace, where a film artist’s only impediment to realizing their vision is the drive to do so.