What Happened to 3D TVs?

Guest Written by George McKechnie PhD, Axiom Home Tech; SmartHomeGallery.com

The video industry bet the farm on 3-D technology—and lost. Several years before his own death, famed film critic Roger Ebert wrote the obituary for this technology in an article titled: “Why I hate 3-D, and you should too.” Ebert noted the reduced light levels and red/green glasses that annoyed viewers, but mostly lamented the creativity-sapping constraints that 3-D imposed upon the film-making process itself. So what happened to 3D TVs?

Instead of 3-D, he argued, we need higher resolution. Sadly, Ebert didn’t live to see it, but today we have ultra high definition (4K) video. We also have vastly improved contrast and color reproduction. Together, they can support an impressive experience of depth—given the right source material—without all the problems that 3-D technology imposed. I first saw this while watching an Ultra HD Blu-Ray disc of The Great Gatsby on an OLED TV display (which offers 4K resolution plus extremely high contrast). In certain scenes, the sense of depth was almost palpable.

How is this possible? Turns out that the human brain has four different ways of perceiving depth. The first is binocular disparity. Because of the distance between the eyes, the brain receives two slightly different images of a scene, which it translates into the experience of depth. This is what 3-D technology relied upon. It’s not unlike the binaural disparity in hearing, where the brain uses the subtle differences between what the left and right ears detect, to create a spacious auditory scene.

A second cue for visual depth perception appears in most scenes. It’s called interposition. The brain knows that an object positioned in front of another object will block the view of that object, and infer that the object being blocked is the one that’s further away. This phenomenon is well known to aspiring actors, who often find themselves interposed in what they had hoped might be a break-out scene.

Renaissance painters relied on a third cue, perspective, to create a visual sense of depth by rendering smaller and smaller, objects that were further and further away, until they vanished—thus the term vanishing point. If you look closely, you may see this depth cue in long outdoor vistas.

But what stood out in viewing The Great Gatsby was the fourth cue: textural gradients. Here’s how it works: When contrast, resolution and color range are sufficient, subtle variations in the color and texture of close-up objects can become clear. This visual richness diminishes for objects that are farther away; and at some point, the texture is no longer visible. These differences in perceived texture between near and distant objects provides rich depth cues which can be quite compelling.

What this means is that the extreme contrast, resolution, and color accuracy which recently became available in source materials and TV displays can—under the right conditions—produce impressive depth, without all the fuss and bother of the failed 3-D technology. Roger would be very pleased.