If you’ve read any of my reviews covering bigger films released during the past few years, you’ve probably noticed that I tend to roll my eyes at the whole “3D” thing. For starters, the terminology is just plain wrong. It is not 3D. It is 4D.
Since the 1950s, the term “3D” has been colloquially used to describe what effects artists call “stereoscopy” – the technique for creating the optical illusion of depth for a flat image. Commonly, a flat image is considered “two dimensional,” depicting only the dimensions generally referred to as “width” and “height” (or if you prefer, “width” and “length,” which is saying the same thing). The addition of depth is therefore said to add a “third dimension” in the form of depth; ergo, 3D.
If this was still the 1950s, that might get a pass, even though it was just as wrong then as it is now. But here in the 21st Century, people really should know better.
Even a flat, still image – i.e. a photograph – is three dimensional, as is a standard motion picture. It’s just that the third dimension being portrayed happens to be the one we all take for granted because we all perceive it in only one direction and generally at the same rate. We call this dimension “time.”
A flat, still image not only shows a scene with perceptible dimensions of length and width, but it also captures a particular moment in time. Three dimensions. A standard motion picture is a series of still images progressing through time. Again, three dimensions. Ergo, flat photographs and traditional motion pictures are, in fact, 3D presentations.
Thus it follows that when one adds depth to the picture, a viewer is now experiencing something in four dimensions: 4D.
It’s basic science. Time is a dimension. Catch up, Hollywood.
[If you’re into M Theory, there are also seven more dimensions to be considered, but since we can’t actively perceive those, I think we can stop at calling it 4D. For now.]