The eye-popping secrets of 'Alita: Battle Angel' — including why James Cameron wanted those big eyes

You had to figure any collaboration between Robert Rodriguez (who brought a graphic novel to life on a digital backdrop in Sin City) and James Cameron (who made Avatar) would stretch the boundaries of technology, and that’s exactly the case with their new futuristic thriller, Alita: Battle Angel, based on the popular manga series.

Set in the 26th century and featuring a lead heroine (Rosa Salazar) with a human head and cyborg body, the film required some serious innovation. “They were constantly having to build new technology to make this come to life, because no one had ever attempted that before,” Rodriguez, the film’s director, told Yahoo Entertainment about its eye-popping effects (watch above).

Speaking of eyes, Alita’s are so large they practically pop off the screen at you — which producer Cameron admitted proved a point of contention (and lightning rod for criticism) at various points throughout the filmmaking process.

“I think Robert and I were both always in utter agreement that she should look like the character in the manga,” Cameron told us. “With our first trailer that went out, we weren’t quite there yet. And we got a lot of blowback from the fans. And there was a backlash reaction at the studio. ‘Better make the eyes smaller.’ I said, ‘No, let’s make ’em bigger.’

“When we expanded her iris and her pupil, she seemed softer, more open, more inviting. You kind of saw through the window of her soul into her character. And then it worked.

Salazar (Maze Runner, Bird Box) provided a cold hard fun fact about how much work actually went into designing her character’s peepers.

“In one of Alita’s eyes, there’s more detail, more mathematics, more geometry, more pixels than in all of Gollum from The Lord of the Rings,” she said.

We’ll go count and report back.

Alita: Battle Angel opens Friday.

Watch James Cameron talk about his upcoming Terminator sequel:

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