

Holography without Lasers: Hand Drawn Holograms (1995) - peter_d_sherman
http://www.amasci.com/amateur/holo1.html

======
wbeaty
> 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](https://www.youtube.com/playlist?list=PL60100E8F3572CEB1)

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

~~~
mistercow
One guy even managed to render opaque surfaces:
[http://blog.robindeits.com/2012/02/20/more-scratch-
holograms...](http://blog.robindeits.com/2012/02/20/more-scratch-holograms/)

~~~
wbeaty
Like mine here?
[https://www.youtube.com/watch?v=XUy8lELWhJg&t=50s](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](http://amasci.com/amateur/hand1.html#331)

------
Jolijn
Ha, strange, I submitted this yesterday:
[https://news.ycombinator.com/item?id=9047015](https://news.ycombinator.com/item?id=9047015)

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

------
glibgil
Gunshot at 0:57
[http://youtu.be/XUy8lELWhJg?t=57s](http://youtu.be/XUy8lELWhJg?t=57s)

~~~
wbeaty
> Gunshot at 0:57

Lol, editing cut.

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

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

~~~
wbeaty
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.

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

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

~~~
wbeaty
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.

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

------
scentoni
I fiddled with this myself a few years ago.

~~~
wbeaty
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](https://www.youtube.com/playlist?list=PL60100E8F3572CEB1)
Still nobody has found one etched on pre-Columbian pottery glaze. Or Egyptian
scrying mirrors! :)

