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margalabargala • today at 5:32 AM • 2 replies • view on HN

I don't understand the distinction. You said it's not a 3d display, then described a 3d display technology.

That's like saying a CRT doesn't display a picture because it energizes pixels only one at a time.


Replies

nomel • today at 6:14 AM

Yes, it's a tech that can be used to display in 3d, but not sure that's the best categorization choice overall.

You can also make things like holographic lenses [1].

And, "display" doesn't seem right. If you recorded a still image, it's a (literal) record of the light field of a scene that lets you view the scene in 3d, like a magnifying glass functioning from all perspectives [2]. You do get the "display" of a 3d scene out of it, when used that way.

Fun fact, you can make your own at home with gelatin, some photo chemicals [3], a laser, and a ludicrously stable table. DIY hologram is going to be one of the first things I do when I retire.

[1] Used in HUDs, like in fighter jets. https://en.wikipedia.org/wiki/Holographic_optical_element

[2] https://www.youtube.com/watch?v=iMdvBmePm9U and https://www.youtube.com/shorts/DnjATyPuFFk

[3] https://holowiki.org/wiki/Dichromated_Gelatin

tliltocatl • today at 6:45 AM

You can do things with holography that are impossible to do with any other 3D display. I. e. comparing two objects for sub-wavelength differences.