The Pros and Cons of Glasses-Free 3D Movies

By  · Published on November 2nd, 2016

James Cameron is pushing for 3D without glasses for future Avatar sequels. Is that, like, even possible?

In an award acceptance speech before the Society of Motion Picture Television Engineers last Friday, director James Cameron proclaimed that for sequels to his blockbuster hit Avatar he would push for greater innovation in cinematic technologies such as high dynamic range, high frame rates and 3D without glasses. This declaration follows the critically lambasted world premiere of Ang Lee’s Billy Lynn’s Long Halftime Walk, a war drama filmed in native 3D, 4K resolution and at 120 frames per second. (See our Tomris Laffly’s review of the film here.) Like Lee, Cameron is known for testing the waters of cinematic advancements and in fact the notion of 3D without glasses, or “glasses-free 3D,” already exists in consumer products. Indeed, 3D has come a long way since the Na’vi first made their way to the three-dimensional big screen, but there is still a long way to go. Here are some things to think about when it comes to this cinematic technology.

Billy Lynn’s Long Halftime Walk and the Challenge of Immersive Cinema

3D movie technology is constantly evolving

Contrary to popular belief, 3D has been around for quite awhile. One of the earliest instances of 3D movie technology were those red and blue 3D glasses that first appeared in the 1950s. According to Wired, this imaging method known as anaglyph involved projecting images on the screen with two color layers superimposed onto one another. When viewed through the red and blue (or cyan, really) glasses, each of the two images reaches the eye it’s intended for, creating an integrated stereoscopic image. The tech was impressive at the time but came with several problems including the loss in image detail and ghosting effects.

This dog gets it (flickr).

Today’s 3D movie systems such as RealD, Dolby 3D and IMAX 3D involve a more advanced system of filters and different projector specificities. (Slashfilm has a great breakdown of the main differences between them.) But these formats still require the viewer to wear 3D glasses which can be bothersome for viewers and costly for exhibitors. Apart from spending on glasses, 3D movie technology requires outfitting theaters with the proper projectors to support systems such as RealD and IMAX 3D. Exhibitors are playing a long game with 3D. They are banking on studios to produce massive event films that they can feature in their 3D theaters. Whether or not consumers will continue to buy into it is the question.

The “sweet spot”

In theory, glasses-free 3D movie technology would create a more organic and cost-effective immersive movie viewing experience. But the technology is only currently available in smaller screen consumer products. The tech involves the use of “parallax barriers” which are a series of slits that allow each eye to see a different set of pixels, creating a sense of depth. The Nintendo 3DS released in 2014 employs this technology. IGN called its 3D effect substantially improved from previous consoles but noted it had an “extremely narrow sweet spot” where the 3D effect actually worked well. The console’s head-tracking camera and infrared sensor is supposed to help widen the 3D sweet spot considerably.

Best seats in the house?

This so-called “narrow sweet spot” is harder to recreate in a large format theater screen. For example, a viewer in Row A Seat 5 will always have a different view of the screen from the viewer in Row Z Seat 35. And what if the “sweet spot” is in Row L Seat 20? How can 3D technology, an illusion that so often depends on lighting, color filters and viewer position, work well in a mass theater setting and without the goofy glasses?

Health concerns and “stereoblindness”

With every technological advancement comes potential health risks. Visual health concerns are a big factor with 3D technology. After the launch of the Nintendeo 3DS, optometrists warned that excessive use of the Nintendo 3DS or repeated viewing of 3D images could negatively impact the eyesight of young children. In 1995, Nintendo’s head-mounted games console Virtual Boy gave many users splitting headaches before it was eventually discontinued and deemed a commercial failure.

Viewers have also reported headaches and nausea when watching 3D movies. In some cases this could likely be “all in your head,” but it is definitely an issues that manufacturers are working to avoid. 3D is an illusion projected on a flat screen, so headaches could be a result of your eyes trying to adjust to the illusion. Some folks are like Johnny Depp, who are reported to have “stereoblindness,” meaning their eyes are not aligned properly and they cannot fully see 3D images. Thus, health concerns and the differences in people’s vision pose another issue when it comes to translating glasses-free 3D to large format theater screens.

Cinema 3D and High Frame Rates

MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) released a paper last July that suggested a prototype for glasses-free 3D on a large scale. The prototype is called “Cinema 3D,” and involves the development of “new physical projectors that cover the entire angular range of the audience.” The key finding of this study is that since, in a movie theater, people are limited by the width of their seat, their heads only move over a small range of angles. Thus, a projector can be created that can cover those various ranges to enable every seat in the theater to successfully view a film in 3D. Here’s a video MIT put together to illustrate this research:

The prototype is just barely larger than a pad of paper but there is great potential here. Whether or not other factors such as viewer height, seating locations, health concerns and other individual factors could affect the tech will hopefully be addressed over the course of more production and research into this technology.

Another advancement that could help in developing glasses-free 3D is higher frame rates. In an interview with THR, Cameron said that rather than use high frame rates as a format – as employed by Ang Lee and Peter Jackson – it should be utilized as a tool. Frame rates are the number of images displayed by a projector in a second. The standard frame rate for film is 24 frames per second (fps). Jackson filmed The Hobbit at 48 fps, whereas Lee filmed Billy Lynn’s Long Halftime Walk at 120 fps. The result is a sharper detail and richer image quality that resembles reality much more closely than 24 fps. To Cameron’s point, higher frame rates would help sharpen and smoothen 3D image, especially during camera movements like 3D panning.

The first Avatar sequel is scheduled for release in December 18, with more films in the franchise set for 2020, 2022 and 2023. Hopefully that gives Cameron, MIT and anyone else working on 3D innovations enough time to develop the tech for us to hang with the Na’vi in hyper-real 3D.

Writer. Audio/Creative Producer. Columnist, Film School Rejects.