If you’re a movie lover, you might have heard a lot lately about Ang Lee’s Gemini Man, and how it used advanced, groundbreaking technology to film it.

So what? you might be thinking, What’s the big deal? It’s true that most tech advancements in filmmaking are ones you don’t really notice in a big way on the screen. But it’s worth paying attention to Gemini Man, a movie that has been struggling to get made for a full 22 years – over two decades – simply because the technology wasn’t advanced enough to pull it off yet.

So What’s The Big Deal About The Technology Behind ‘Gemini Man’?

The script for the film, originally written by Darren Lemke, had been floating around Hollywood since 1997. Since then, a number of studios picked it up only to drop it, and a number of directors had hopped on board only to back out. Almost a dozen A-list actors had been attached to the lead role before Will Smith was cast. Harrison Ford, Sean Connery, Chris O’Donnell, Mel Gibson, Jon Voight, Nicholas Cage, Brad Pitt, Tom Cruise, Arnold Schwarzenegger, Sylvester Stallone, and Clint Eastwood were all set to star at one point or another. All walked away from the film that was impossible at the time to make. But now it’s 2019 and Ang Lee and Will Smith are finally bringing it to life.

The challenge is that it’s not just one type of cutting-edge technology Lee is using in his film, it’s multiple. First, there’s the most obvious: the de-aging technology used on Will Smith to make a younger dopplegänger clone of himself. Then you add the 3D format and the high-def 4K resolution and high frame rate (HFR) of 120fps and you’re looking at a movie that utilizes visual technology in a way no other film has to date.

Allow me to break down the different types of tech and why Gemini Man is paving the way for the future of movies – and where it still has major limitations.

What Makes The De-Aging In ‘Gemini Man’ So Different Than Other Movies?

A digital Will Smith as ‘Junior’ in Ang Lee’s ‘Gemini Man’ (Courtesy: Paramount)

It’s not like de-aging a character hasn’t been around for a while. Disney, especially with Marvel, has been at it for years, offering us everything from a de-aged Robert Downey Jr. scene in Captain America: Civil War to de-aging Samuel L. Jackson for the entirety of Captain Marvel. Most recently, we’ve seen it utilized in Martin Scorsese’s boundary-pushing The Irishman, set to hit theaters and Netflix in November.

The process for Gemini Man, however, is vastly different than anything that has been done before. For its de-aging of characters, Disney uses a motion-capture performance from its actors and then digitally de-ages them – think an exceptionally detailed and realistic, high-level paint job, with the actor as the canvas and the digital technology as the paint. For Kurt Russell’s de-aged scene in Guardians of the Galaxy Vol. 2, the process involved a mocapped Russell, some clever prosthetics and makeup, and another, younger actor. Russell would do the scene, while another actor, Aaron Schwartz, would study his gestures and expressions. Makeup was put on Schwartz and he’d do the same scene while mimicking Russell. The actors’ performances would then be composited together, with Aaron’s skin being digitally layered over Russell’s performance.

Gemini Man utilized a completely different process. In fact, one could say it wasn’t de-aging at all, but a completely distinct creation. Junior, the younger version of Will Smith’s character, Henry, isn’t simply Will Smith in mocap suit (Smith did have to hop into the suit and facial rig, but it was to collect data for the animators). Instead, Lee worked with the famed Weta Digital to build Junior as an entirely digital, CG creation made from scratch using old footage of younger Will Smith as reference. Smith still provided all the voice work, but the visuals on screen are completely digital. (Fun fact, to help with the realism of a younger Will Smith, Lee used to show Smith old performances of himself and tell Smith he needed him to act like he did when he was just in his 20s and less experienced – i.e., be rawer and less good at it.) It’s more accurate to compare Junior to the animals in the live-action Lion King than to any of Marvel’s de-aged actors.

But as I mentioned, that was only one part of the technology that sets Gemini Man apart from other movies.

What Does 4K Resolution Mean And How Does It Work?

Benedict Wong as Baron and Will Smith as Henry in Ang Lee’s ‘Gemini Man’ (Courtesy: Paramount)

This is where it gets technical and complicated, but I’ll try not to bog you down in too many dirty details. Bear with me as I attempt to put this all in layman’s terms. Hopefully, you’ll walk away after having read this piece with a deeper understanding of how modern movies are shot. Sound good? Excellent.

First, let’s talk about resolution. Resolution, at least when we’re talking about it in digital video recording, essentially refers to spatial resolution. This is measured by the pixel count in a digital image. Other video formats count their resolution vertically, but digital cinema format counts its resolution horizontally. A full aperture, digitized film frame is exactly 1024 pixels, so each format is 1024 times that format across. A 2K format is 2048 pixels wide, and a 4K image is 4096 pixels wide, etc. The more pixels you can fit into a frame, the more detail you can include in the picture. That’s what gives hi-res images their crispness and clarity. Think of the difference between 8-bit images and video games today. Same thing in movies, essentially, just with photographed pixels instead of CG ones.

The crispness and clarity of the 4K resolution of Gemini Man is evident from the very first scene, a daylight shot of Will Smith’s character posted up on a hillside waiting for his next sniper target. Every line in his hands is shown, every pore on his face and tiny facial tic. It’s so clear it actually takes a minute for the eyes to adjust – but once you do it’s a visual wonder.

It’s not just resolution that made the image so crisp, however. The high frame rate Lee used also contributed.

What’s Does High Frame Rate Mean And How Does 120fps Work?

Will Smith as ‘Junior’ in Ang Lee’s ‘Gemini Man’ (Courtesy: Paramount)

Hand-in-hand with resolution goes frame rate. Frame rate refers to the number of individual video frames a camera can capture per second. You’ll see it denoted as “fps,” meaning frames per second. It’s a throwback to the days of silent film, where movies were recorded on a reel of film stock and camera operators would hand-crank the film as it recorded – literally, the reel spinning or “rolling” around as the cameraman cranked it is where we get the phrase “cameras rolling.” Later, movie theater projectionists would play the movies back at the same frame rate at which they were recorded, like a giant flipbook. Every frame is another page, eventually blending together to form a moving picture.

Since 1927, the standard frame rate for film has been 24fps. Most films are shot in 24fps but projected back with three-bladed projectors to make it 72fps, meaning every single image is flashed three times on screen, reducing flicker. The video below is about film projectors rather than digital, but it’s a great explainer on how projectors project:

Some movies have experimented with HFR (high frame rate) in recent years. Peter Jackson famously shot his Hobbit movies in 48fps, a then-controversial choice that divided audiences. But still the industry standard, as it has been for the last 90 years, is 24 frames per second.

Ang Lee, however, chose to shoot Gemini Man at an eye-popping 120fps. Why? Because it’s excellent for action movies.

First off, it makes action sequences look more lifelike and smooth as there’s no motion strobing. The same goes for slow-motion. Typically, slo-mo sequences are shot in 60fps and then slowed down to 24fps or 30fps in post-production to create the slow-motion effect without seeing any choppiness between frames. Shooting in 120k allows slow-motion scenes to unfold with even more smoothness and clarity.

The result is that using HFR, like resolution, results in an incredibly lifelike image on the screen. Think of it this way: The resolution determines what the image looks like on the screen but the frame rate determines how that image looks when it moves on screen. The higher the resolution and the higher the frame rate, the more realistic the movie appears. The two work in tandem in Gemini Man to create a movie that is as close as we’ve come yet to approximating how our human vision works in real life.

Still, just because the technology is groundbreaking doesn’t mean the rest of the world has caught up, especially not in North America.

U.S. Theaters Lag Far Behind In The Technology Needed To Project ‘Gemini Man’ Properly

Mary Elizabeth Winstead (Danny) and Will Smith (Henry) in Ang Lee’s ‘Gemini Man’ (Courtesy: Paramount)

Like most evolutionary leaps forward in history, it turns out we’re not quite ready for what Ang Lee brings to the table in Gemini Man. Lee belongs to a small but passionate class of filmmakers who have long pioneered advancements in movie technology and who have incorporated it into the very foundation of their work: James Cameron, Andy Serkis, Peter Jackson and Jon Favreau can all consider Lee a fellow techie. Sometimes that passion has ushered in truly game-changing movies, such as Cameron’s Avatar, or Serkis’ entire body of work since Jackson’s Lord of the Rings trilogy. Sometimes it shows the limitations of technology as it currently stands, such as the visually stunning but emotionally stunted CG animals in Favreau’s The Lion King.

The clearest and most immediate limitation of Gemini Man is a simple one: Theaters simply aren’t ready for it.

Lee shot his movie in 3D at 120fps and in 4K, and that’s how he intends for audiences to see it. But American theaters lag far behind when it comes to projection technology. In the grand scheme of things, digital is still very new – it’s been less than 10 years since most theaters switched from film to digital projectors. Even now, a number of theater chains and independent cinemas are still getting used to 4K, even more when you add in other advanced projection formats. Despite Paramount warning theaters earlier this year to prepare themselves, most simply don’t have the capability to screen Gemini Man as Ang Lee shot it, with 3D AND 120fps AND 4K. For audiences in the U.S., screening Gemini Man is like the old joke that you can pick any two but never all three.

Currently, theaters equipped with Dolby have the ability to project at 120fps…but only 14 theaters in the entire United States have that Dolby-equipped capability (Polygon has a list of those theaters here). However, those theaters will only be capable of projecting the 120 frames per second in 2K resolution rather than 4K. Likewise, almost every 3D HFR screening will be projected at 60fps instead of 120fps – technically a high frame rate, but still half the speed. When Gemini Man premiered at the TCL Chinese Theatre in Los Angeles, Paramount had to outfit the theater especially to ensure it was projected as Lee intended.

However, that’s not the only challenge Gemini Man faces. It’s not just theaters that aren’t ready for what Lee is bringing: Human beings aren’t, either.

We’ve Been Conditioned To Watching Movies In 24fps

Clive Owen as Clay Verris and a digitally created Will Smith as Junior in Ang Lee’s ‘Gemini Man’ (Courtesy: Paramount)

I mentioned The Hobbit above for a reason. When it was released in 2012, a fair bit of the criticism from both film critics and audiences was that the 48fps was jarring and took viewers out of the film. For all that new TV models always tout crystal clarity as a selling point, turns out that when it’s on the big screen, it can be disconcerting.

The reason doesn’t have so much to do with what our eyes and minds can handle, but what we’re used to handling, at least in a cinematic format. You’ll hear plenty of people talking about how 24fps is more pleasing and natural to the eye but that’s simply not true. The human eye is capable of processing so much more than what even the most advanced cameras can capture, with the ability to react to visual signals in less than a millisecond. There is some debate among cognitive researchers about just how much visual information the human eye can capture and process, but it’s still multiple times higher than what movies provide. Likewise, the real world doesn’t have to worry about frame rate because it’s true movement we’re seeing – there is no need for triple-bladed projectors or motion smoothing.

The reality is that for the entire history of cinema, however, we’ve been watching movies at the industry-standard 24fps so that’s what we’re conditioned to seeing when we watch a movie. The same preconditioning challenges also happen in regard to higher resolution, which provides infinitely more visual information to our brains than we’re used to processing when watching a movie (in the same Polygon article, Lee mentioned it was 40 times more data than normal), even though it’s still far less than our brains process in real life. The result is that when we watch Gemini Man in 120fps and 4K, even though it’s closer to how we naturally see the world than any other movie, it may seem unnatural (I say “may,” as it depends on the person – some people adjust to heightened visual stimulation faster than others). Just like it took audiences a while to adjust to 3D, there will be an adjustment period as moviegoers get used to high frame rate and increased resolution.

But adjust they’ll have to. Like anything else, there is no stopping forward momentum or progress. Movies like The Hobbit and Gemini Man or even James Gunn shooting Guardians of the Galaxy Vol. 2 in 8K might be the outlier examples for now, but they are the forerunners of what’s to come. Just like movies making the jump to 3D, or when silent films moved to sound, and black-and-white film moved to color, eventually modern audiences will catch up with the technological wonder that is high frame rate and high resolution. In the meantime, Gemini Man gives us an excellent taste of what’s to come.

Gemini Man is in theaters this weekend. Get your tickets now.