Christopher Nolan’s Dunkirk, which is likely to accrue some nominations during awards season, was designed to be an immersive experience. Shot largely with IMAX cameras and optimized for 70mm projection, it’s meant to showcase the latest cinema technologies, which is a little ironic for a period piece. Given the focus on World War II-era aerial combat and naval maneuvers, Nolan and his crew had to use modern high tech to depict 1940s low tech. Films about WWII have been hitting screens since shortly after that war started, but Nolan is reimagining the classic war films with better planes, boats, and cinematography. So how do Nolan’s planes compare to the ones in early award-winning WWII movies?

1942’s Casablanca and 1946’s The Best Years of Our Lives were both shot in black and white, and neither film is about combat conditions the way Dunkirk is. But aircraft play a significant part in the plots of both films. In Casablanca, planes move the forces of oppression to and from the Moroccan city, and represent the best hope of escape for lovers and patriots. In The Best Years of Our Lives, planes symbolize the war left behind. Both films have quite a few aircraft on camera, largely shot from the exterior. The rare interior scene in Best Years has three men gathering in front of a projected image to look at the landscape below. They exclaim that they can see a golf course and a high school, but it’s hard to make out anything they’re describing among the nondescript trees and open fields the camera pans over.

But while planes flit by the screen like speedy insects in 1940s-era films, in Dunkirk, a solid third of the story is devoted to observing the movement and interior experience of fighters, namely RAF Spitfires. Through subtitles, the film announces from the beginning that it’s going to spend an hour in the air, a week on land, and one day in the water. Of those three different settings, only the air battles are simulating real time.

High tech in this instance doesn’t mean CGI and green screens, but actual RAF Spitfires made available to Nolan and his crew. Dunkirk’s primary pilot characters (played by Jack Lowden and Tom Hardy) handle these fighters in soaring environment shots and close battles. Where older films were often limited to a single plane on-screen at a time, Dunkirk focuses on proximity for wingmen and opponents, and keeps the planes’ interiors highly visible. Instead of green screen, Nolan actually had the planes go up with IMAX cameras mounted on their wings.

The dogfights in Dunkirk are delivered to the audience play-by-play, as if they’re in the air with the fighters. Nolan explains in a behind-the-scenes featurette that this is all his master plan: “That intimate physicality, that tiny cockpit, to be in there for an hour or two, we really focused on that as being one of the most important aspects of the film and putting the audience in that seat, which is an extremely difficult thing to do.”

It’s a sharp contrast to the filming days of Casablanca, when videography in airports was restricted, and most of the film had to be shot inside a studio. A scalable model of a Nazi airplane, with a tail-mounted swastika, is shown as the major disembarks, while a real plane with a fake registration number flies in a different shot. Shooting during the war, Casablanca’s producers didn’t have access to real German planes, so they had to swap in the US-made Fokker Super Universal airplane.

The secret to enjoying Dunkirk — this slow-burning, stressful experience focused solely on a slew of young, nearly identical men — probably lies somewhere in appreciating how modern technology has made the cinematic experience more personal for viewers, who are being taken places they couldn’t go with previous filmmaking tools.

Correction August 6th, 10:00PM ET: The story has been corrected to note that The Best Years of Our Lives used a projector, not a green screen, which hadn’t been invented yet.