Thanks to modern digital effects, there's essentially nothing that can't be made real in the movies. However, it's possible that's all being taken a bit too far. It turns out that a scene as simple as the mid-credits sequence of Captain Marvel, which required no special effects whatever, was actually done with a green screen.
The scene shows Captain America, Black Widow, and War Machine in the aftermath of Avengers: Infinity War. They're clearly still figuring how just how much damage has been done, but they've picked up Nick Fury's pager from the post-credits scene of that film and are monitoring it to see what it's all about. After the pager's battery dies, the team turns around to see Carol Danvers.
It turns out that, the two sides of the interaction were filmed separately and combined in post-production, as when Brie Larson did her side of the filming, she was all alone. According to Larson...
There was nobody else there — I was by myself on a green screen. I walked in, and they were like, 'Just real quick, we're just going to whip pan over to you and you're gonna go, 'Where's Fury?'
Brie Larson even says she was so in the dark on what was happening with the scene, she had to clarify just how she was asking the question? Was Fury in the room? Was he close by? Was she asking for directions or an explanation? Things were being so closely guarded at the time that she had very little information about what was going on with the scene.
It seems like an odd step to have to go to, to film the scene on a green screen, but Brie Larson tells The Tonight Show Starring Jimmy Fallon, that since she actually filmed Avengers: Endgame before she filmed Captain Marvel, and there wasn't even a script for Marvel at that point, there really wasn't much of a choice.
If the mid-credits scene had been written, it could have been filmed during the production of Endgame, but since nobody knew they needed the shot, the green screen was the way to go, it was easier then getting all the Avengers together to film one scene.
Over the past two months Marvel fans have been sure to catch up on Captain Marvel. It's made over $1 billion at the box office and is the last chapter of the Marvel Cinematic Universe before Avengers: Endgame opens this evening. We've seen Captain Marvel return to earth, but what happens once she gets there? The answers will finally be revealed tonight. If somehow you still haven't caught Captain Marvel, it's still in theaters and you can probably still catch it before Endgame opens.
Check out Brie Larson's complete comments on The Tonight Show in the video below.