It’s called “Stereo,” not “3D”

When speaking or writing about the entertainment industry’s current gimmick du jour, please refer to it correctly as “stereoscopic 3D” or “stereo 3D.” If there is no chance of confusion with stereo audio (and honestly, how often do we talk about stereo audio any more?) you may simply use “stereo.”

What you may not, however, call it is “3D.”

The term “3D” can, obviously, refer to anything three-dimensional. In the case of films, TV, and video games, it has usually refered to “3D graphics”; the rendering of three-dimensional objects and scenes as viewed through a virtual camera. We’ve had numerous successful 3D animated films (with Toy Story being the first feature-length example), and almost every big-budget live-action movie now uses 3D graphics for special effects. Since the advent of the PSX/N64 generation, a majority of video games have used 3D graphics.

Thus, when I hear otherwise-intelligent people asking whether we will soon be seeing “3D video games,” I cringe. We already have 3D video games – or are games like Half-Life and Mario Galaxy now “2D” simply by virtue of the movie industry’s latest marketing campaign?

Those of us who understand what words mean have a responsibility to use them correctly. This is the only way we can hope to stem the tide of those who use words they don’t understand, incorrectly.

Special Addendum for Pedants

Some readers might want to split hairs and point out that the “3D” graphics I refer to above are always projected onto a 2D screen. It would seem, then, that stereo graphics is “more 3D” by virtue of adding a sense of depth to an image that already has height and width.

This argument is entertaining (as most pedantic arguments are), but ultimately misses the point … or rather, two points:

  • The “3D” in 3D graphics doesn’t refer to the final projected image, but to the object or scene that is being rendered. The dimensionality of the content and the final projected image don’t need to match. You can have a 2D projection of 3D content, just as you could have a stereo projection of a 2D image.
  • Projected stereo graphics are not, in the mathematical sense, three dimensional. There are merely a sum of two two-dimensional projections. Adding a depth component to a flat image doesn’t change its dimensionality either. Crumple up a piece of paper and it is still a 2D surface.

In the end, the only method of projection that could reasonably lay claim to the name “3D” would be some sort of omnidirectional holographic projection (and researchers are working on various experimental display technologies of this sort). Still, if such displays ever became commonplace, we’d be better off calling them “holographic.”

So there you have it, stereo “3D” apologists (if there are any); your nomenclature doesn’t have a leg to stand on – not even a pedantic and wobbly one.