The Odyssey sparks backlash as viewers realise they're not actually seeing the full movie

People who rushed to theaters to see Christopher Nolan's The Odyssey adaption have come to the conclusion they've been cheated – and it brings up a little-known detail.

The film is based on Homer's ancient Greek story, which tells the tale of Odysseus, a Trojan War soldier on a mission to return home to Ithaca after a decade away from his loved ones.

With major star power, the flick stars the likes of Matt Damon, Tom Holland, Anne Hathaway, Robert Pattinson and Lupita Nyong'o, which has actually led to some controversy surrounding historical accuracies and casting choices.

However, what has viewers up in arms about the Ancient Greek story, isn't necessarily about the plot itself.

It plays into the fact that many people believe they have ended up not seeing the entirety of the flick.

Now, this might sound odd, considering the three-hour-long feature is screened for its duration, but it's more so because it is the first film to be shot in its entirety on 70mm IMAX film cameras.

Nolan told The Independent that this had been a long time coming, as he has wanted to do this since he was young.

“It’s been a very long journey, starting with The Dark Knight,” said the director. “That was the first film where we were able to go to IMAX and say, ‘Lend us your cameras. Let’s try this on things like the introduction of the Joker, the truck flip.’ But we couldn’t do the dialogue scenes because the cameras are very, very loud.”

He added: “So knowing we were doing The Odyssey, I went to IMAX and said, ‘Look, if ever we’re gonna do a whole film on IMAX, this is the movie to do it with’.”

But this has led to some fans to share that the viewing difference between an IMAX screen and a traditional cinema screen, means they're seeing less than other people.

This is because IMAX shows the whole frame, while a traditional screen is smaller, and cuts the surrounding border from scenes.

One person online joked about the missing parts: “How am I supposed to watch not knowing that Agamemnon helmet-mogs Odysseus only in IMAX?”

This means that if you're not seeing the film at one of the 25 theaters in the US that can accommodate the 70mm IMAX viewing, you're not seeing the whole thing.

These locations include Arizona's Harkins Arizona Mills & IMAX, California's Regal Hacienda Crossings & IMAX, and Colorado's Cinemark Carefree Circle & IMAX.

You're probably wondering what the difference is between the 70mm IMAX camera and a standard one.

As reported by Desert Sun, a standard film strip is 35mm, which means that the 70mm film is physically bigger, and a higher resolution picture – creating an expanded image.

So, when you're watching it in an IMAX theater that's specifically designed to view the 70mm strip, you're seeing more of the frame than you would in a normal theater.

On the flip side, if you're watching it in a theater designed to show a 35mm strip, you're losing half of the strip on the screen.

Technically, that means you're not seeing the 'full' film because you can't see the whole frame.