Mask used for stunts in Indiana Jones and The Dial of Destiny is giving people nightmares

A mask used during the production of Indiana Jones and the Dial of Destiny has been giving fans 'nightmares' online.

In the age of wall-to-wall CGI, there's still no replacing the real feel produced by a practical effect in a movie.

A straight up comparison between the Lord of the Rings and Hobbit films, for example, can show how strange CGI sometimes looks next to top-notch practical effects.

However, sometimes such effects can look a little... interesting before post-production works its magic on them.

And a mask used in the new Indiana Jones movie has shown just that.

Twitter/@IndianaJones_ch

The mask was worn by stunt doubles so that they would look more like star Harrison Ford. The effect would then be completed in post, and make the process easier than replacing the face altogether.

However, before post-production, they look somewhere between Michael Myers from Halloween and an old-school alien from Doctor Who.

And viewers were quick to pick up on the uncanny valley appearance of the mask, which featured both an old version and a young version for flashback scenes.

One person wrote: "Seeing this right before bed on the night I saw the movie. 1000% nightmare fuel."

Another joked: "They should hand them out at each screening."

Meanwhile, a third pointed out the resemblance to a certain villain, saying: "Paint it white and you have a whole new Halloween franchise."

And a fourth said: "On one hand, this has been a thing for a while, on the other SWEET JESUS."

Despite looking creepy, the masks also received some positive feedback, with fans remarking that they were still an improvement compared to an over-reliance on CGI.

One said: "Looks better that the CGI face…"

Twitter/@IndianaJones_ch

Another wrote: "Long proud history of these in movies. I'll take these over CGI any day because at least the brain knows there's a real person in the shot."

"Horrifying, but at least movie magic blends this in, unlike CGI where it's almost always recognisable." someone else commented.

Nonetheless, there was no denying that the masks were pretty horrifying to look at despite how fantastic they might look once the editing process was complete.

And it's not the first time that movies have taken an unusual approach when it comes to replacing the faces of actors in movies.

Stars Wars franchise movie, Rogue One, also featured the regenerated faces of Peter Cushing as Grand Moff Tarkin and Carrie Fisher as Princess Leia.

The film drew some criticism for 'resurrecting' the actors for their appearances instead of recasting the roles or writing around the characters, so there wouldn't be the need to use the technology.

And director Gareth Edwards responded to the criticism, telling CNN in 2017: "I think it’s fair enough and you should tread carefully around this area.

"We felt like we weren’t recreating Peter Cushing so much as we were recreating Tarkin, like a character he’d already established and we were doing our damnedest to pull from his performances to tell the story."