Director Christopher Nolan has made no secret of his preference for film over digital capture and projection, but his latest project Dunkirk is going to represent something of a high-water mark. According to Variety, the World War II drama will be projected on 70mm film in 125 theaters, topping the 100 theaters that showed Quentin Tarantino’s The Hateful Eight back in 2015. That makes it the widest 70mm release in 25 years.

The film, which chronicles the evacuation of Allied soldiers from Dunkirk, France, represents Nolan’s most ambitious use of film formats to date. While he’s utilized IMAX film cameras for sequences in films like The Dark Knight and Interstellar, with Dunkirk Nolan shot the entire film on a combination of IMAX 65mm and traditional 65mm film. The latter format has seen a bit of a mini-renaissance lately, with Paul Thomas Anderson also using it for The Master.

How many different formats are there?

Where things get complicated is tracking just how many different formats Dunkirk is getting released on. Along with standard 70mm film projection, which offers an ultra-wide 2.20:1 aspect ratio, the movie will also be screening in what’s being referred to as “IMAX 70mm.” That’s basically just the classic, old-school IMAX format, where the film runs through the projector sideways, for an even higher-resolution image and a towering 1.43:1 aspect ratio. In addition to that, it will be projected in IMAX Digital — which depending on your theater can mean several different things.

If your local venue offers IMAX’s new laser-projection system, you’ll be seeing the company’s highest-quality digital presentation, with an aspect ratio of either 1.9:1 or 1:43:1, depending on the size of the theater screen (I told you this was going to get complicated). The traditional IMAX Digital presentation, which is the IMAX variant most commonly found in multiplexes, will lack the expanded color gamut and brightness of the laser screenings, and will be at an aspect ratio of 1.9:1. And outside of that, the movie is also being screened in both traditional digital projection and on 35mm film.

Which format is the one, true Dunkirk? Nolan is known for relentlessly checking the quality of his films across the different distribution mediums, but in this case we’re talking about a film that was shot natively on two different 65mm formats. The ultimate expression of Nolan’s vision is no doubt the IMAX 70mm, with the traditional 70mm presentation running right behind. The problem is that IMAX 70mm screens are remarkably hard to find in 2017. Fortunately, Dunkirk’s own ticketing site makes it nice and easy to figure out which of the premium formats is showing where — and tickets are on sale now. The film opens on July 20th.