During tonight’s election coverage, CNN pulled out some deep tech, displaying Jessica Yellin live via hologram. I looked closely and wasn’t even able to see the R2 unit behind the scenes.

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My original impression of how this works is below. A comment from Eric suggests that this might actually be a real hologram that Wolf can see in person, and not a live bluescreening effect. More on this at the end of the post.
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From what I can tell (and I could be wrong), this is done using a combination of technologies, most of which you could simulate at home if you could be satisfied using standard equipment, some careful camera work, and post production techniques instead of the real-time hardware and networked camera equipment CNN is rocking.

The person is recorded inside of a blue or green tent surrounded by an array of cameras that are able to catch several angles at once, presumably with each camera partnered with a real camera on the studio stage. The appropriate holo-camera feed is chosen depending on the real studio camera being used, and the holo camera is networked and synced to move exactly with its partner camera in the studio. This allows the hologram to shift perspective appropriately as the studio camera scoots around the stage. You might compare this to how the virtual first down line is tweaked in real-time to fit the various camera positions in a football game broadcast, except in this case it’s not a generated asset, it’s a live video feed that’s carefully filmed to be at the exact perspective.

Finally, using traditional keying/blue-screen techniques, the tent background color is alphaed out of the feed and the video is overlayed on top of the studio feed, leaving the keyed-out hologram correctly perspective positioned on the final output.

There are two final added touches that make this pretty convincing. One is the red circle on the floor. My best bet is that it’s real and created with a red light from above in the live studio feed. The second is the person-to-person conversation. Wolf Blitzer is a pretty good actor – there’s no way he’s actually seeing the hologram in front of him.

Or can he? Eric points us to the Musion Eyeliner and Cisco Telepresence technology that can display what appears to be a fairly high-fidelity hologram in a stage environment. Here’s a video that shows how such a system would be set up:

I remain a bit unconvinced that this is actually what’s going on, mostly because of the full 180 degree camera POV that was used in the CNN version, but doesn’t seem possible with the Musion system. What are your thoughts? Please post them in the comments.

Anyone care to make their own hologram video with a moving camera? It’d be a bit of a challenge using consumer equipment, and I’m not sure what software you’d use if you didn’t have something like After Effects, but it’d be pretty fun to see. For inspiration, here’s a decent one done with a fixed camera position:

CNN Hologram Interview [via MAKE]
Real Life R2D2 Hologram

Cisco Telepresence Demo On Live Stage
Musion Eyeliner Hologram Projection System