Whether Tupac and Michael Jackson holograms deliver the heebie jeebies or a dose of nostalgia, one has to admit, the technology is impressive. But how does that work? And are these really holograms or just projections?
Of course, not all holograms on the stage are posthumous ethical riddles. The technology was used to simulate performances by Janelle Monae and MIA, to stage the Gorillaz avatars with Madonna on stage, and to bring to life fictitious stars like Hatsune Miku.
Sorry, these are not holograms.
Let's clear up the air very quickly. There is a lot of discussion about what a hologram is or not. For the sake of argument, we therefore adhere to a very simple definition of the word hologram.
Holograms are free-standing 3D light structures. They are not projected onto a surface (that would make them a 2D surface), but they can be disseminated through glass, science fiction moon crystals, or other objects that do the work.
So, Princess Leia's secret message in Star Wars? That's a hologram. The spirit of Michael Jackson? This is not a hologram ̵
In both cases, these holographic concerts are a step in the right direction But the holographic performances of Tupac, Janelle Monae, MIA, and others are based on a 1860s salon scare called Pepper's Ghost, which is a simple Victorian trick Masses, plays and parties have been extensively applied, and you've seen it in action at Disney's Haunted Mansion, if you've ever been to Disneyland.
The ghost of Pepper's Ghost is literal smoke and mirrors (well , minus the smoke.) A reflective glass panel is placed on a stage and in the direction of a hidden Kabi I'm inclined. When the hidden cabin is lit, it reflects an image on the glass, which then reflects the image towards the audience. At eye level this picture would look crumpled (remember that the glass is angled). But because the audience looks at the stage, the picture looks "correct", with a ghostly, translucent quality.
Of course, your Pepper's garden-style ghost trick requires an actor. The last time we checked, Michael Jackson was dead, so we can assume the technology has changed a bit.
Musion Eyeliner Projections
Musion Eyeliner sounds like a shitty local band, but is actually a patented, modernized version of the Pepper's Ghost Trick. And in a way, it's even easier than Pepper's mind.
Rather than relying on secret spaces, actors and glass to project people onto a stage, the Musion Eyeliner Trick requires only a projector and a thin Mylar sheeting.
First, the Mylar sheet is placed in front of a stage at a 45-degree angle. Then a projector in front of the stage shoots a picture on the Mylar sheet.
And that's all – somehow. These projections also require a source video. Ideally, the source video is completely silent and creates the illusion that a performer is on stage. This can be done by recording a performance with a still camera or by creating an expensive 3D model and then upgrading to singing and dancing (the holograms by Tupac, Jackson and Roy Orbison are 3D models).
Problems with the Technique  Apart from obvious ethical dilemmas, Musion Eyeliner has many technological flaws and weak points:
- Phase Problems : The most elaborate Musion eyeliner holograms use multiple projectors to make a picture so wide and detailed as possible. However, these projectors must work together perfectly. If you fall out of phase, it ruins the picture.
- Wavy Screens : Musion eyeliner holograms are based on a thin mylar screen that "blows" like a flag when hit by a strong gust of wind. This is very easy to observe in the Michael Jackson hologram video, in which the entire stage looks like under water.
- Viewing angle : Again, the viewing angle of the audience determines whether a Musion eyeliner hologram looks "correct" or "pinched". "Viewed from the side, these projections can look flat like paper.
- Lighting : Musion eyeliner projections are best for dark or dark environments. The problem is that they always produce bright pictures, which in itself is not a big deal. Holograms in dark environments, however, can look ridiculously light and flat – especially when real people wander around the stage (as shown in the Tupac performance).
- Cost : Setting up a Musion eyeliner hologram does not cost much. The rebuilding of famous figures in 3D, however, costs a ton of money (the Tupac 3D model cost about $ 400,000). Even in a sold-out auditorium, it's hard to recoup that kind of expense.
You probably should not judge Musion eyeliner holograms for their technical flaws. The fact that wind can ruin these projections is a sign of how young this technology is. The Future of Holograms A hologram TV prototype showing a human heart. 19659003] Currently, most of your favorite electronics companies spend tons of money on augmented reality. From Instagram filters and Pokemon Go to spooky undead musicians, we're increasingly approaching the inevitable: real 3D holograms.
It's hard to know when real holograms will become common, but they can be used for entertainment over the next few years for a few decades. We already know that there is a market for hologram concerts. The BBC is also researching hologram TVs (basically, they are small 3D versions of Pepper's Ghost Tricks).
At the moment we are just waiting for the technology to be a little bit mature. When this happens is unclear. In the meantime, we have to live with (and get used to) creepy posthumous concerts and Hatsune Miku.
Sources: Christie Digital