[iamleppert]

They say it's not a parlor trick, but it's nowhere near true holography or anything like it. True holography records the object's wavefront as a flat interference pattern, encoding the phase information from the object (and also creating a very precise model of its surface), creating a diffraction grating which can then be used to replay the identical wave when illuminated by a suitable reference source of light.

This is the only known way to create true images with real depth of field and parallax, and requires ultra high resolution to both record and display the microscopic interference pattern.

There is a good book https://www.crcpress.com/Ultra-Realistic-Imaging-Advanced-Te... that has the mathematical basis for which the real principle of holography could be applied, given a capable enough display technology, to re-create an exact replica of the light field/wavefront that is identical to what we see in real life. Of course, a single static image with sufficient resolution of about 3"x5" in real life contains over 100 GB of data. The information carrying capacity of light is amazing.

None of the current VR/AR systems (including MagicLeap) use anything close to what is required, and we are still ways off in both display tech and GPU bandwidth to even generate a single, static image in a consumer product.

[Animats]

There's a small company in Austin, Zebra Imaging, which generates CG holograms on big pieces of photographic film.[1] Those are real holograms. The military buys them as 3D models in a flat, portable form, and they're sometimes used in place of architectural models. Some people still take photographic holograms using a big flash laser. (This was a thing about 40 years ago. One guy still does it.) Almost everything else called a "hologram" is about as fake as a "hoverboard".

Someday someone may make a display with light-wavelength-scale resolution and display real holograms in real time, but that hasn't been done yet.

[1] http://www.zebraimaging.com/

[amazon_not]

I found this interesting. Too bad the prints are like $250/$500 each depending on whether they are monochrome or color. Wasn't easy to find out either, what with their expired webshop domains and all.

[anotheryou]

They look pretty good with the right lighting, but objects must never be clipped by the papers edge. So you have to keep your 3d inside an imaginary pyramid on top of the medium.

[Retric]

That's just a question of how wide the paper is.

[anotheryou]

Practically: if the paper is wider, it will probably lower your viewing angle and that stuff is expensive!