"I never did any of those green-screen things. It's just, it's amazing. I mean I have a whole new appreciation about acting. It's not easy. There's nothing there," Douglas said on Thursday.
The actor then described the challenge in having to imagine the scene around him while filming in front of a green screen.
"The director tell you, 'Right here, here it comes now. There's a missile flying right at you right now.' So you really feel like you're way over the top," he said.
"It's a whole other process. I'm really enjoying it," he continued.
Douglas portrays Hank Pym in the Ant-Man movies and is returning alongside Paul Rudd, Evangeline Lilly and Michelle Pfeiffer for the third entry in the series titled Ant-Man and the Wasp: Quantumania.
The film is set to be released on Feb. 17, 2023. Douglas mentioned to Fallon that he will begin filming the project in about three weeks in England.