James Cameron intentionally cast shorter people as extras in Titanic for one important reason

James Cameron has revealed why he only hired shorter people as extras in Titanic.

Christmas is the perfect time for sitting down, grabbing a mince pie, mulled wine and rewatching all of the classics.

While you may normally stick to festive fun such as Home Alone or iconic franchise like Harry Potter, if you've been getting a bit sick already of the snow and cheese-filled films, then why not add a gut-wrencher like Titanic to the list?

And there's one fact about the 1997 classic you may not have noticed or realised the significance of before.

You may already be such a Titanic fan you know why Cameron thinks Kate Winslet - who played Rose - was 'traumatised' by the movie.

And, if you care about the film and Leonardo DiCaprio's Jack at all, you'll have heard about the 'scientific study' Cameron used to answer the question which has plagued us all for year - could Jack have actually fitted on the door frame?

However, what you probably won't have realised until now, is why the movie had a very specific requirement for its extras.

In an interview with Los Angeles Times, Cameron reflects on the making of what was, at the time, the most expensive film ever made, noting one way which helped keep costs lower while not taking away from the grandeur of the film - and in particular it's set.

Paramount Pictures/ 20th Century Fox

The famed director reflects: "The scale of everything was beyond anything we could imagine in terms of our prior experience.

"At the time we thought, wow, there’s no way this movie could ever make its money back. It’s just impossible."

However, the team did make one alteration to the set to help reduce costs slightly, and that was compromising on 'the three degrees' tilt of a set, instead replacing it with two different sets at two different levels to represent the ship pre and post striking the iceberg.

And it certainly helped, with producer Jon Landau noting: "We saved $750,000."

Paramount Pictures/ 20th Century Fox

But did this impact how huge the ship looked and how horrifying it's sinking appeared on screen?

Thankfully not, and this was because the team decided to only cast 'short extras' under the height of 5ft 8 inches which helped make the set look 'bigger'.

Cameron reflects: "It’s like we got an extra million dollars of value out of casting."

Well, that's another fact to add to the memory bank for your next Christmas quiz!