Holography without Lasers: Hand Drawn Holograms (1995) | Hacker News Reader

Holography without Lasers: Hand Drawn Holograms (1995)

amasci.com

> fiddled

So did lots. Three people managed to automate, one even non-trivial. Also, it's mass produced from metal master: on a vinyl album release of Jack White 'Lazaretto' (with rotating angel by Tristan Duke of MIT Media Lab)

Here's a long youtube playlist of scratch-holo: https://www.youtube.com/playlist?list=PL60100E8F3572CEB1

Still nobody has found one etched on pre-Columbian pottery glaze. Or Egyptian scrying mirrors! :)

Thanks for the list! I'm gonna play around with this concept, seeing that I just managed to etch my first letter on a CD case.

Something not in the original http://amasci.com/holo/ site is the discovery that if you scratch complete circles rather than arcs, then rotate the whole plate under the light, the hologram rotates around an axis normal to the plate. https://www.youtube.com/watch?v=UtmGgmhWBAc

One guy even managed to render opaque surfaces: http://blog.robindeits.com/2012/02/20/more-scratch-holograms...

Like mine here? https://www.youtube.com/watch?v=XUy8lELWhJg&t=50s

When people at work angrily insisted that these were not true holograms because you can't make opaque objects, I sat down and drew opaque objects. This was around ?1996? Instructions from published paper: sect. 3.3.1 http://amasci.com/amateur/hand1.html#331

My google skills are failing me--I can't find examples of automated creation of them.

Can the scratches be created by a laser cutter? Or is there something special about the etch of a sharp point?

Ha, strange, I submitted this yesterday: https://news.ycombinator.com/item?id=9047015

It's a form of arbitrage, I suppose, if not coincidence.

Gunshot at 0:57 http://youtu.be/XUy8lELWhJg?t=57s

> Gunshot at 0:57

Lol, editing cut.

http://youtu.be/XUy8lELWhJg?t=34s

The really anomalous thing is the big 60/120Hz pulse at 0:37, click above. I was shooting out front of the house, and I reviewed the whole video while standing there, and found the 120Hz. WTF!? It had to be EM, there'd been no audio like that while filming. Was I painted by a uWave beam?

I'm right near airports, also a couple miles north of a Boeing mil black project building. But radar is clicks, not 120Hz. And it sounds like changing PWM during the pulse.

To me it just sounds like a car or motorbike driving by.

That was my first thought ...while standing out there checking the video a few seconds after shooting. But it was confusing me, because there was no motorbike. I'd been trying to shoot without car noise, so I was facing the road, and (mostly) waiting for any vehicles to pass. When cars pass you can hear the loud wind/wheels hiss in this vid. I noticed that weird hum even in my tiny camera speaker. Later I checked for it indoors, and still there.

I suppose I should check the frequency. If not right at 60/120Hz, and has doppler of moving vehicle, then it's much more likely to be a bike(etc.) that I'd not noticed down the road, and then my brain had edited out while I was talking. Finally, there's a power line about 20ft up on the other side of the street. Huge current surge? The usual b-field from that thing is so strong that any small pickup coil in my house will detect it, and for sensitive work I have to go to the back of the kitchen, over 100ft distant.

Also, I've found that modern smart-phone microphones are better than than my ears.

These holograms are essentially a set of overlaid Fresnel lenses, and they work by the same principle?

Same principle as Benton white-light holograms, see 2003 SPIE paper linked on the site, also "Not true holograms?" The scratches are line-scatterers, not flat-bottomed as Fresnel, so no focal length.

Basically it's an enlarged Zoneplate rather than a fresnel lens. Arrays of curved line-scatterers can reconstruct single pixels with programmable depth. The fringes of Rainbow holograms do this, and their 3D image-reconstruction requires no interference nor monochromatic illuminators. Insight: change the spacing of the fringes of a rainbow hologram, or even randomize the spacing, and the 3D reconstruction still works fine. The 3D image doesn't depend on optical interference. A very weird effect! So, can we draw a Rainbow hologram by hand with a needle, by scratching the fringes with random spacing? Yep. We get 3D images, but they're white in color with no rainbow artifact.

Amazing. Just tried it with scissors and a CD case. Got a proof-of-concept working :).

I fiddled with this myself a few years ago.

So did lots.

Three people managed to automate, one even non-trivial. Also, it's mass produced from metal master: on a vinyl album release of Jack White 'Lazaretto' (with rotating angel by Tristan Duke of MIT Media Lab)

Here's a long youtube scratch-holo playlist: https://www.youtube.com/playlist?list=PL60100E8F3572CEB1 Still nobody has found one etched on pre-Columbian pottery glaze. Or Egyptian scrying mirrors! :)

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