It’s NOT a Hologram, Folks!

The legendary rapper, Tupac Shakur, made an appearance at Coachella in California last weekend, in spite of the fact that he’s been dead for more than 15 years. He performed on stage alongside Snoop Dogg, including a “live” shout-out to the Coachella audience. Putting aside the creepy factor of performing with dead singers, let’s talk briefly about the technology.

Let me say at the outset that even though I was not there, it appears that this production was a triumph of technology. The creators apparently combined video recordings and computer animation and audio manipulation to create a completely new performance by the rapper. It is impressive, to say the least.

What I wish people would not say, however, that it is a “holographic” image. Just Google “Tupac hologram” and see how widely the term was used to describe this production. As I understand the technology, it is not a hologram; there is no 3D component to the display. It is simply a 2D image projected onto an invisible screen. It’s not clear if it’s rear or front projection, or if perhaps there is some sort of beam-splitter material involved. But in any case, it is not a 3D hologram. When you move your head from side to side, you see different views of the object; you can see details on the side of the object that were not visible before. With a projected image like this, it may look like 3D because you can move your head and see objects placed behind the image, but the image does not change. It’s as if it were constantly turning to face you, no matter where you move.

If you’re too close to the projection screen, you can see a strangely distorted image:

TheĀ image of Tupac appears strangely thin from this angle.

This is not the first time that the press has incorrectly named this sort of production a hologram, and I don’t expect it to be the last. But I still wish that they’d use the term correctly.