How do IT Chapter Two’s child actors still look so young?

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“It’s better to shoot it two years later than five years later,” director Andy Muschietti told Total Film.

“But in those two years, they grew up quite a bit. Not all of them. Sophia [Lillis] looks exactly the same. Jaeden [Martell] looks pretty much the same. Finn grew up quite a bit, and he’s a tall guy.

"They’re at the age where a week difference makes their voice drop, they hit puberty, suddenly their nose sticks out and they have a moustache. So three years later, we reunite with them and they had grown, some more than others,” he added to HuffPost.

Their solution? Go down the route usually reserved for decades-old flashbacks in big superhero or sci-fi movies, and de-age their teenage actors digitally with help from pioneers Lola Visual Effects (who did similar techniques for various Marvel movies).

In other words, they’re using the same techniques used to make Will Smith look like his 20-something self in Gemini Man and Michael Douglas look 30 in Avengers: Endgame, but to reverse just a couple of years for their younger cast.

“From the beginning, we knew that that would be part of the budget, the visual effects to address that,” Muschietti confirmed.

“I’ve seen this movie so many times. I saw ‘Chapter One,’ like 300 times. So I know where the nose of [young Eddie actor] Jack Grazer goes. I know where his smile is in relationship with his chin. So we did a lot of work together with Lola, but it was fun,” he said.

“It’s all about making their heads bigger. That’s the trick, that’s the proportion trick, giving them bigger melons,” producer Barbara Muschietti added.

In the finished film, the effect is reasonably seamless. Unless you’re looking very closely you probably won’t notice anything different about the kids in their appearances, though for our money Ben (Jeremy Ray Taylor) did probably look the most different from his first-movie self.

Notably, Finn Wolfhard’s younger Richie was pretty indistinguishable from the original – the big glasses probably help – but there was one clue that we weren’t quite seeing the truth in the new movie.

And actually, it doesn’t come from the digital de-ageing but from the sound design. In a flashback scene set in the Losers’ Club’s underground clubhouse, Richie (Wolfhard) and Eddie (Shazam’s Jack Dylan Glazer) end up squabbling – and if you happen to be in a cinema with a good sound system you might notice that their voices sound a little off and re-dubbed, especially in comparison to co-star Sophia Lillis.

The reason? Well, if you’ve seen Stranger Things lately or Shazam!, you’ll know that Glazer and Wolfhard’s voices have both broken since the time they filmed the first film, meaning that their lines had to be altered and/or redubbed in postproduction to match their earlier performances in this follow-up.

On-screen, this isn’t too noticeable, but in a scene where they loudly bicker over the top of other, less altered (or unaltered) actors the difference can be noticed.

Overall, though, IT Chapter Two pulled off an impressive and groundbreaking bit of digital de-ageing. Clearly, it’s not just Pennywise who can create arresting illusions…

IT Chapter Two is in cinemas now