In fact, this is a two-dimensional video image projected on a curtain of water vapor produced by an ultrasonic humidifier hacked onto a laminar flow nozzle made out of a bunch of drinking straws.  Not strictly a hologram, but still a very cool thingum.  It’s the work of Chris Weisbart, aka YouTuber ChristopherTalosian, and comes to us via Mike Senese, who provides this description:

Based on the concept behind commercial units, but using everyday items (drinking straws, scrap PVC pipe, a kid’s humidifier from the thrift store, some scrap computer fans), he rigged up a device that creates a thin, even sheet of vapor mist. Almost translucent, but able to catch the light projected onto it from a rear-facing projector — which gives an eerie, floating hologram effect…

A similar technique uses a piece of thin muslin as a screen, as for instance in this haunt-prop “Shining” twins illusion.  [Thanks, Mike!]

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