Upcoming horror threequel 28 Years Later is far from the first Hollywood movie to be shot with the help of an iPhone, but it might just be the first shot on 20 iPhones. That’s how many phones director Danny Boyle had mounted on a special rig for select shots in the movie, which releases June 20th.

For Boyle, shooting on iPhones is more than just a gimmick. He returns to the series after directing the 2002 original 28 Days Later, which was shot on a digital video camcorder, a meta nod to the fact that this was how home videos were shot at the time. He and returning cinematographer Anthony Dod Mantle took that as an “influence” in choosing to shoot partially on a phone, the camcorder’s closest modern equivalent.

It was first reported last year that Boyle had shot 28 Years Later on an iPhone 15 Pro Max, but according to IGN the movie actually uses a mix of regular cameras, drones, and iPhones, including three special rigs designed to hold eight, 10, or 20 iPhones at once.

“There is an incredible shot in the second half [of the film] where we use the 20-rig camera, and you’ll know it when you see it,” Boyle told IGN. “It’s quite graphic but it’s a wonderful shot that uses that technique, and in a startling way that kind of kicks you into a new world rather than thinking you’ve seen it before.”

Boyle calls the 20-phone rig “basically a poor man’s bullet time,” explaining that it allowed the crew to shoot some of the film’s more violent scenes in new ways. “It gives you 180 degrees of vision of an action, and in the editing you can select any choice from it, either a conventional one-camera perspective or make your way instantly around reality, time-slicing the subject, jumping forward or backward for emphasis.”

It’s not the film’s only unusual cinematographic choice. It was also shot in an especially wide 2.76:1 aspect ratio, the equivalent of 70mm film, to keep viewers guessing about where the film’s infected could pop up: “If you’re on a widescreen format, they could be anywhere… you have to keep scanning, looking around for them.”