CNN made quite a splash tonight with their “holographic” interview of Jessica Yellin by Wolf Blitzer. But is it real?

Wolf Blitzer interviews a hologram of Jessica Yellin

Not quite. Yes, CNN was capturing 3D information at the interview site by surrounding Yellin by 35 high def cameras. But despite what you saw on the screen, Wolf Blitzer was not actually seeing her in the studio. He was seeing her on a screen (just as we were), much as a weather reporter sees a projection on a green screen. In exactly the same way, Yellin’s 3D image was fed into the cameras video stream. The trick – the position of the camera was being tracked so that as it moved, the incoming video was changed based on the position of the camera and the 3D data.

So what you’re really seeing is a green screen effect. A really cool one, but it’s not a real holographic projection in the studio. At least not yet.

Don’t worry though – true 3D holographic TV is coming. Recent work at the University of Arizona has led to the development of holographic media that can be rewritten. Right now it takes several minutes to rewrite a holographic image – a long way from the 30 frames per second you’d want for a TV image. But will you one day have a flat screen true holographic TV? It seems increasingly likely.