Alternate name for disc-shaped stereograms?

favalora · Post by **favalora** » Thu Mar 29, 2012 3:06 pm

Hi -

ARGH. Can you help me remember the name of something I learned very recently, and forgot?

I come from the land of electronic displays, particularly autostereoscopic displays. Our language is a little different. There's a family of such displays that is shaped like a disc, lies flat like a table, and offers parallax only "in the round." That is, the imagery is computed for a circle of viewing points. I've taken to calling these "theta-parallax-only displays." Here are some examples (but promise me you'll come back after looking at these videos) http://g-fav.blogspot.com/2012/03/360-d ... hstar.html

Okay, welcome back.

What is the name of hologram similar to this?

I am not thinking of "multiplex hologram," though it may indeed be multiplex.
The particular name I am trying to remember sounds odd; maybe Greek in origin. Goodness, I don't even remember what letter it starts with. I vaguely recall seeing it in a paper from the 1970s or 80s.

I went through my two SPIE volumes on collected papers on Holography, and the one on CGHs, and couldn't find it.

-Gregg

holorefugee · Post by **holorefugee** » Thu Mar 29, 2012 5:40 pm

The only one I remember was a disk made in Mylar and it was a rotating transmission rainbow with a mylar mirror. I thought it's brand was HoloDisk but Bob Hess has one in his collection. It was of a woman taking off her clothes but just before it was x-rated the loop would start over.

The video you show shows an image formed above the film. An image can appear above the film but not outside the films field of view. In other words the film has to be the background. Of course you know this.

Dinesh · Post by **Dinesh** » Thu Mar 29, 2012 6:27 pm

holorefugee wrote:The only one I remember was a disk made in Mylar and it was a rotating transmission rainbow with a mylar mirror. I thought it's brand was HoloDisk but Bob Hess has one in his collection. It was of a woman taking off her clothes but just before it was x-rated the loop would start over.

That's "Lovely Rita" by Craig Newswanger. If I'm right, that Rita is what you're remembering, then it was not a rainbow, it was a reflection.

I believe Gregg is talking about an electronic display, as opposed to a holographic display a la Rita. Am I right Gregg?

favalora · Post by **favalora** » Thu Mar 29, 2012 7:44 pm

Hi -

(Thanks for trying!)

I really am asking about a hologram, not an electronic display, in this case.
It is really killing me that I can't come up with this name. I saw it in an old grainy paper that used a name which I swore sounded like Greek or Latin roots meaning "see from all the way around." Grrrr.

-g

favalora · Post by **favalora** » Thu Mar 29, 2012 7:56 pm

Ah!

My recollection was really faulty - - this was really about holographic data storage, not display holography: PERISTROPHIC HOLOGRAM
http://authors.library.caltech.edu/3846/1/CURol94b.pdf (1994)
"...a method of multiplexing holograms by rotating the material or, equivalently, rotating the recording beams"

Okay, move along, nothing to see here...
-Gregg

Ed Wesly · Post by **Ed Wesly** » Fri Mar 30, 2012 9:13 am

What a word! I promise to use it in a sentence today! Too bad there wasn't a picture of the final hologram in the paper!

The Craig Newswanger device was called Holodisc or maybe with a k, or maybe even with a r in a registered trademark circle. They were reflection holograms, some on Polaroid photopolymer, the most infamous being the Lovely Rita mentioned above. There might have even been a Spiderman, and at the 1994 LFC ISDH he displayed an homage to Buckminister Fuller called Bucky's Pyramid.

Dinesh · Post by **Dinesh** » Fri Mar 30, 2012 10:40 am

There was a Spiderman (we have one), but I believe that the Spiderman was made by Ryder Nesbit. We have an embossed version, so it could be that Craig made a reflection piece on photopolymer and Ryder made a resist version for mass production. I do remember that Ryder told me that Craig hired him to try and get colour into Rita but Ryder was never succesful.

favalora · Post by **favalora** » Fri Mar 30, 2012 10:46 am

Ed you crack me up.

Well, you'll need to find a special circumstance to use that fancy word because I think it''s aimed toward data-storage, rather than display.

g

Dinesh · Post by **Dinesh** » Fri Mar 30, 2012 2:54 pm

favalora wrote: Well, you'll need to find a special circumstance to use that fancy word because I think it''s aimed toward data-storage, rather than display.

g

The Windmills of your mind (one word altered)
Round, like a circle in a spiral
Like a wheel within a wheel.
Never ending or beginning,
On an ever spinning wheel
Like a snowball down a mountain
Or a carnaval balloon
Like a carousell that's turning
Running rings around the moon

Like a clock whose hands are sweeping
Past the minutes on it's face
And the world is like an apple
Whirling silently in space
Like the circles that you find
In the PERISTROPHICs of your mind

holorefugee · Post by **holorefugee** » Sat Mar 31, 2012 9:09 pm

Lovely Rita must be right. I would love to buy one...