Robert Downey Jr.'s final appearance in the Marvel Cinematic Universe came in last year's Avengers: Endgame, and while he'll no doubt miss playing Tony Stark, it doesn't sound like he has fond memories of Iron Man's helmet. Talking to David Letterman, the actor revealed that it was so uncomfortable to wear during Iron Man, he refused to don it during future MCU projects.
"Initially, everything was really there," Downey reveals in the below clip from Netflix's My Next Guest Needs No Introduction with David Letterman.
"They wanted to spend as little as they could on CG replacement," the actor explained. "So I remember this helmet went on, and there'd be a shot, and I'd be in this whole suit, and they'd say: 'All right, Robert, it’s like you landed on the roof, so when we say action, just go like that, like you just landed, and then start moving forward."
"Then these LED lights went on and it was like Manchurian Candidate. I was absolutely blinded."
By the time Avengers: Endgame rolled around, he was done with that helmet. "They’d just be like, 'Hey, Robert, would you mind putting on... 'Helmet?! No! Yes, no. Put two dots [on my face], and then you can paint it in later.'" That's fair enough given what a brutal experience wearing the helmet sounds like, and it's no secret that in later years, the Iron Man suit was primarily VFX.
In fact, special effects are now so good that even Spider-Man's suit is often created solely with them, so the days of actors wearing uncomfortable costumes could be nearing an end!