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Holography is a very particular set of 3d image rendering technique. This volumetric display is not holographic. To me it's a frustration. Microsoft's highjacki

by chmike 8y ago

Holography is a very particular set of 3d image rendering technique. This volumetric display is not holographic. To me it's a frustration. Microsoft's highjacking of the word holography is also frustrating. Such abuse does not server the product and it's inventors. Truly holographic displays will emerge once we can control ligth interference in the display.

dosy 8y ago
> Truly holographic displays will emerge once we can control ligth interference in the display. Could you explain this a bit more please to give an idea of the path to get there?
- _ph_ 8y ago
  Not the poster above, but I will try a short explanation. You see an object, because light goes from its surface (either emitted or reflected ambient light) to your eyes. You see it in 3 dimensions, because the light differs by the viewing angle. Holography is a technology of recording the light "emitted" by the object. The light has to be recorded in direction and intensity. This is done via interference between the object light (waves) and a reference light wave, which usually is a planar wave of light. This interference creates an interference pattern, which can be recorded by film. The trick is, that if you develop the film to get the black and white pattern, you can shine the reference wave onto the film and it interacts with the interference pattern such that the object wave is reconstructed. A hologram such is an exact recording of the light emitted by the object. This is something the display tries to emulate by offering 64 different images, but not quite the same. As the interference pattern is just a greyscale image, one could use an ultra-high resolution lcd display to synthesize that - there have been demonstrators of that, but I am not aware of a large holographic display so far.
  - dosy 8y ago
    That's a great explanation, thanks. For the way you described it, to me, it doesn't sound that hard. - Create interference pattern - Record interference pattern - Shine ref light onto pattern to recover emitted light If done perfectly would this yield a convincing hologram (what I might try to describe as "visual sense impression of real 3D object being present" ) ? What are the major limitations in the current technology? You said it might be possible for high end screen, does that mean there is hologram tech out there? I have never seen any demonstrated. Is there some sort of information processing problem that software could solve on the interference pattern? Or is this more a physics problem -- maybe we do not have the materials that can do the steps required?
    - _ph_ 8y ago
      The catch is, that the patterns have the resolution of the wavelength of light. You cannot take plain black and white film for this, you would need extremely high resolution film material. Agfa actually produced special film for holograms for a while, high contrast and very high resolution, but with a sensitivity like ISO 10. The resolution is far higher than normal LCD screens offer and that would be the main impediment. The math for calculating the interference patterns is almost trivial, but the scale is massive. Doing it in real-time would still require quite high-power setups, as you would have to calculate hundreds of rays per "pixel".
      - dosy 8y ago
        This is so interesting, thanks. From my photog background, yep ISO 10 would be very tough to work with.
pndy 8y ago
Volumetric display isn't as appealing as holographic when it comes to marketing. And masses often don't care about details, they just want to be thrilled that each day technology brings us closer to Star Wars-like holograms.

by chmike 8y ago

dosy 8y ago

> Truly holographic displays will emerge once we can control ligth interference in the display. Could you explain this a bit more please to give an idea of the path to get there?

_ph_ 8y ago
Not the poster above, but I will try a short explanation. You see an object, because light goes from its surface (either emitted or reflected ambient light) to your eyes. You see it in 3 dimensions, because the light differs by the viewing angle. Holography is a technology of recording the light "emitted" by the object. The light has to be recorded in direction and intensity. This is done via interference between the object light (waves) and a reference light wave, which usually is a planar wave of light. This interference creates an interference pattern, which can be recorded by film. The trick is, that if you develop the film to get the black and white pattern, you can shine the reference wave onto the film and it interacts with the interference pattern such that the object wave is reconstructed. A hologram such is an exact recording of the light emitted by the object. This is something the display tries to emulate by offering 64 different images, but not quite the same. As the interference pattern is just a greyscale image, one could use an ultra-high resolution lcd display to synthesize that - there have been demonstrators of that, but I am not aware of a large holographic display so far.
- dosy 8y ago
  That's a great explanation, thanks. For the way you described it, to me, it doesn't sound that hard. - Create interference pattern - Record interference pattern - Shine ref light onto pattern to recover emitted light If done perfectly would this yield a convincing hologram (what I might try to describe as "visual sense impression of real 3D object being present" ) ? What are the major limitations in the current technology? You said it might be possible for high end screen, does that mean there is hologram tech out there? I have never seen any demonstrated. Is there some sort of information processing problem that software could solve on the interference pattern? Or is this more a physics problem -- maybe we do not have the materials that can do the steps required?
  - _ph_ 8y ago
    The catch is, that the patterns have the resolution of the wavelength of light. You cannot take plain black and white film for this, you would need extremely high resolution film material. Agfa actually produced special film for holograms for a while, high contrast and very high resolution, but with a sensitivity like ISO 10. The resolution is far higher than normal LCD screens offer and that would be the main impediment. The math for calculating the interference patterns is almost trivial, but the scale is massive. Doing it in real-time would still require quite high-power setups, as you would have to calculate hundreds of rays per "pixel".
    - dosy 8y ago
      This is so interesting, thanks. From my photog background, yep ISO 10 would be very tough to work with.

pndy 8y ago

Volumetric display isn't as appealing as holographic when it comes to marketing. And masses often don't care about details, they just want to be thrilled that each day technology brings us closer to Star Wars-like holograms.