Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms • Hacker News Board

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#21

Post by captainmuon » Thu, Mar 18, 2021, 4:34 PM UTC

Pretty neat. This seems like it actually exposes holograms the "hard" way, like you would do in a traditional setup (with lasers and beam splitters). A shortcut would be too directly print the very fine pattern that is on the holographic plate - basically a fourier transform of the image you want to encode. When I was in university we did a student's project on computer generated holograms and tried that - with a special ultra high dpi slide printer it didn't work, but strangely with a regular laser printer. The resolution was too coarse and the scale of the hologram was off, but it was really cool - if you reflect laser light from the plate, it looked as if the object was really there.

I the appendix we speculated that it might be possible to clevery use GPUs ("3d accelerators" back then ;-)) to do the calculation in realtime and show it on a very high DPI screen. Some time I'd really like to revisit the project with today's technology.

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#22

Post by hologram-paul » Thu, Mar 18, 2021, 4:35 PM UTC

DivisionSol wrote: post #15

I'm on the verge of contributing to the Kickstarter, trying to get a sense of what I'm seeing: 1) http://www.litiholo.com/images/buzz-on-the-printer-crop-809x... Wondering what the artifacting is on the left side of the hologram itself? Is this a problem with this specific hologram, or will all holograms have this artifacting? 2) Same image, but I'm not quite sure Buzz is centered in the middle of the ... work plate?…

The artifact you are seeing is a test alignment hogel on these early holograms. Do not expect that in the final system. Likewise, the demo holograms had different border areas, and some with fingerprints (definitely cleanable). The film plate will need some border area. Still working on where we will be with ease of hackability.

Thanks for the compliments! Hope to see you as a backer and please recommend to the maker spaces you know.

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#23

Post by tinus_hn » Thu, Mar 18, 2021, 4:36 PM UTC

Would be nice if this would become available as a reasonably priced service for a one off print

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#24

Post by Grustaf » Thu, Mar 18, 2021, 4:36 PM UTC

hologram-paul wrote: post #12

larinzod wrote: post #9

Cool idea. But I'm not seeing a practical application outside of the "hey this is cool!" factor.

I have often used the comparison to early personal computers. The things were mainly switched and lights, but there was potential for where it could go. I heard that even early Apple people would say "A computer in every household", and people would ask, "What would I do with a computer?" and their best answer was "It's a great way to store and file your recipes."

I love holograms, always found it extremely fascinating, but this is not really an argument. Anything _could_ sort of become the next personal computer, the question is why you think specifically holograms are useful?

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#25

Post by filmor » Thu, Mar 18, 2021, 4:37 PM UTC

camjohnson26 wrote: post #16

Maybe this is the wrong definition but I read “true hologram” to mean a 3D image made of light, this looks more like one of those images that used to be on the cover of Guinness World Records. Edit: I see OP is the founder and this is a smaller project. Looks really cool and sorry if that sounded negative! Just not what I expected from the title.

"3d image made of light" is decidedly not what a real hologram is. Have a look at the Wikipedia page, real holograms are so much cooler!

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#26

Post by hologram-paul » Thu, Mar 18, 2021, 4:40 PM UTC

captainmuon wrote: post #21

Pretty neat. This seems like it actually exposes holograms the "hard" way, like you would do in a traditional setup (with lasers and beam splitters). A shortcut would be too directly print the very fine pattern that is on the holographic plate - basically a fourier transform of the image you want to encode. When I was in university we did a student's project on computer generated holograms and tried that - with a spe…

Actually, recording the laser light is easier currently than trying to compute out the full fringe pattern and print. In essence the light and interference pattern captured are doing real time Fourier computation at the speed of light.

3D computational advances certainly have helped, and we expect even more as our hologram printers get more advanced with time. Thanks.

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#27

Post by vorpalhex » Thu, Mar 18, 2021, 4:41 PM UTC

camjohnson26 wrote: post #16

Maybe this is the wrong definition but I read “true hologram” to mean a 3D image made of light, this looks more like one of those images that used to be on the cover of Guinness World Records. Edit: I see OP is the founder and this is a smaller project. Looks really cool and sorry if that sounded negative! Just not what I expected from the title.

I believe you are thinking about a light field display if you want the Star Wars esque living 3d projections of light.

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#28

Post by hologram-paul » Thu, Mar 18, 2021, 4:42 PM UTC

tinus_hn wrote: post #23

Would be nice if this would become available as a reasonably priced service for a one off print

Definitely might be part of where things could go! And I'm sure there will be people who get one of the 3D Hologram Printers for doing just that. Holograms-as-a-Service?

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#29

Post by hologram-paul » Thu, Mar 18, 2021, 4:45 PM UTC

mikepurvis wrote: post #20

hologram-paul wrote: post #19

Earlier quoted context omitted.

Where the 3DS is lenticular, these are real laser-formed holograms, and can be seen by multiple viewers without any headset or other gear. Right now view zone is 45 degrees.

Huh, very cool— is it totally passive then, once "printed"? It seems like you're encoding into each pixel what it would have to be for every possible view angle, and I'm having trouble getting my head around how this works.

Hogels record the intensity and direction of the light (giving the ability to "look around" the hologram object).

Yes, this hogel information is permanently exposed onto the hologram film.

Re: Show HN: LitiHolo – a desktop 3D hologram printer that makes true holograms

#30

Post by BeniBoy » Thu, Mar 18, 2021, 4:47 PM UTC

What I think is missing from the demo is that we can only see "lateral" movement, which is the reason why many people here think this looks like a lenticular display. If that is a real hologram you should be able to change your viewpoint vertically as well right ?

Super cool anyway !