It’s easy enough to spot the CGI when Harrison Ford shows up in a movie and the 80-year-old actor suddenly looks like a spry 45 — a very real thing that happens in Indiana Jones and the Dial of Destiny — but “digital de-aging” has seeped surprisingly deep into the bedrock of Hollywood.

“There are many instances of de-aging on television shows that most aren’t even aware of,” VFX artist Yoshi Vu tells Inverse. “Not for the sake of flashbacks but simply to make the actor look younger or more attractive, the same way makeup is used.”

Then again, sometimes it’s very noticeable. Decades after we first saw characters like Indiana Jones and Luke Skywalker on the big screen, their original actors are still portraying them in sequels and spin-offs. And in some cases, Harrison Ford and Mark Hamill appear as they did back in the days of the originals.

To understand the art of digital de-aging, and how it’s colliding with unprecedented issues facing the special effects artists today, Inverse interviewed two experts about the process, the challenges, and how rapidly advancing technology could totally overhaul the industry.

One of the very first successful films in movie history was a Western. Released in 1903, The Great Train Robbery launched a genre that dominated Hollywood for almost a century, inspiring massive blockbusters like True Grit and Butch Cassidy and the Sundance Kid more than 50 years later.

But its influence extends beyond other Westerns, too. The Great Train Robbery’s final shot of an outlaw firing at the camera even inspired a similar moment in Martin Scorsese’s 1990 mobster classic, Goodfellas. So it’s only natural that Scorsese would eventually get around to making what he’s called the first Western of his career.

A great American tragedy of entitlement, greed, and corruption, Martin Scorsese’s Killers of the Flower Moon is a saga of astonishing scope and psychological depth that, in many respects, demands the blockbuster treatment. Arriving in theaters later this year as a three-and-a-half-hour, Oscar-primed epic, it’s already one of the year’s biggest “event” films. And yet, Scorsese takes a more subtle, sophisticated approach to the story than one might expect, given the magnitude of its production.

In the process, Killers of the Flower Moon subverts both his own artistic tendencies and the Western genre. It is a remarkable step forward for the 80-year-old filmmaker, who reimagines the potential of the big-screen epic to reckon with history.