Printing vs Making Holograms

DigiFlash · Post by **DigiFlash** » Mon Dec 21, 2009 4:02 pm

Hello fellow Holographers,

I'm working with Rabbitholes (and worked before with Geola and XYZImaging) always been responsible for printer development.
I'm still coming from Holography, even though I never considered myself an holography artist, but rather laser engineer,
holographic printer engineer etc.. But that's not why I called the topic Printing vs Making Holograms.

Now, I'm not sure how lively this forum is, but still, worth trying.

How many holographers consider printing holograms from pictures and computer generated data anyhow substitute for the "Real holography"?
After all, that's somehow similar to comparing the old good photography to printing picture on the printer... no magic.
And of course, it's restrictive on material, processing, and sometimes it's just not looking good enough...

Another aspect of this is the price. I know, that sometimes the holographer would use some second hand lasers, and basement lab to do some hologram, and
it is definitely has the charm, something is missing, when you do holograms as your business, even more missing if you just send them to "Hologram printing company".
So, I would appreciate any perspectives on pricing, which structure, price level would be acceptable for holographers out there?

As a catch, I can say that I do have some freedom to make "promotional" pricing for holographers and arrange for printing any kind of data available.
I'm open to any discussion on the subject, and any comments are welcome!

BobH · Post by **BobH** » Mon Dec 21, 2009 5:06 pm

I've made holograms the old fashioned way (without sand) in my home and professionally, and built hologram "printers" (at home and at Simian Company). When I'm operating an old fashioned set-up, someone provides an object and design brief, and I make a hologram. When I'm operating a "printer", all someone needs to provide is the object (in the form of data), and I make the hologram. When it's MY image being recorded, I decide everything and make the hologram.

Holographers make holograms. Artists make art. Designers make products. Marketers make lies. Businessmen make money. That's why holographers are pissed that artists, designers, marketers and businessmen have stolen the word "hologram" from us to describe what they do using non-holographic techniques and devices. Just my opinion.

DigiFlash · Post by **DigiFlash** » Mon Dec 21, 2009 5:34 pm

BobH wrote:Holographers make holograms. Artists make art. Designers make products. Marketers make lies. Businessmen make money. That's why holographers are pissed that artists, designers, marketers and businessmen have stolen the word "hologram" from us to describe what they do using non-holographic techniques and devices. Just my opinion.

Well, if the world would be that simple... Holographic artists, Hologram marketers, Hologram businessmen... that's just second level...
And the fact is that CNN and Holographic projections create and use big chunk of formerly your "territory".
At the same time, instead of finding out if this is real hologram or not, it would be more efficient to try to position yourself a bit more specifically, try to highlight the art, the uniqueness, the 3D, or any other aspect of your holograms..

As far as our technology - well, we do record holograms, using lasers, ref and obj beams etc... though some will prefer to call them stereograms, I believe...

BobH · Post by **BobH** » Tue Dec 22, 2009 4:38 pm

What "chunks of (holographer's) territory" are CNN and "Holographic projections" using?

You at Rabbit Holes are certainly making holograms, which is what I call them too, and unfortunately you're stuck with all the problems of real holography in the real world. Lighting, light pollution, display in public, installation, damage by sunlight, color changes over time, color changes with light angle, high cost, and outrageous expectations from the public thanks to marketing bastards and Hollywood.

Good luck!!! I mean that with all respect for the work you guys are doing, which I think is fantastic.

Tom B. · Post by **Tom B.** » Thu Dec 24, 2009 8:24 am

Looks VERY interesting!

As for printing vs making - I thought Andy Warhol solved this when he said we are all stardust [citation needed for bogus quote]

- Is vertical parallax at all possible? I am hooked on making true 3D Denisyuks, but .. I could imagine stereographic scenes that would work too.
- output medium is photopolymer or ?
- what is the size limit on a single frame output image (no mosaic) and what would be the effective resolution at that size.
- any inherent output pixel grids to keep in mind to avoid unfortunate resampling artifacts? Or put another way,
what aspect ratios and XY resolutions have you found to work best.
- Can I send you a bunch of frames and somehow preview the expected result from various angles? It would be nice if this was automated.

holo_cyware · Post by **holo_cyware** » Fri Dec 25, 2009 5:22 pm

Vertical paralax it's certainly possble as i've seen it, but it requires tremendous time for printing the "holopixels" (hours).

DigiFlash · Post by **DigiFlash** » Sat Dec 26, 2009 6:06 am

Tom B. wrote:Looks VERY interesting!
As for printing vs making - I thought Andy Warhol solved this when he said we are all stardust [citation needed for bogus quote]

- Is vertical parallax at all possible? I am hooked on making true 3D Denisyuks, but .. I could imagine stereographic scenes that would work too.
- output medium is photopolymer or ?
- what is the size limit on a single frame output image (no mosaic) and what would be the effective resolution at that size.
- any inherent output pixel grids to keep in mind to avoid unfortunate resampling artifacts? Or put another way,
what aspect ratios and XY resolutions have you found to work best.
- Can I send you a bunch of frames and somehow preview the expected result from various angles? It would be nice if this was automated.

Hardware-wise, our printers are full parallax able, but we chose to optimize the software to process single parallax. There're certain drawbacks, especially for holographers, but very often requirement of rendering would be prohibitive for most other clients, especially at the level of detail (realism) we can print.

We use the film somehow similar to PFG-03c, specifically developed for us.

You mean single tile of the hologram? We have printed 3.6m wide by 2m high with two stripes of film, i.e. our film is limited in height at 1m. For practical purposes, it is probably better to limit horizontal too. Resolution for anything 1m high or more is 1.6mm square pixels. It is very hard to see the difference between 0.8mm and 1.6mm from 2-3m distance, except for some special objects... text..

Pixels are 1.6mm size, so, obviously, they would produce some "fringing" with structures similarly spaced, otherwise, not much to comment on this one, once you render the images, it is quite obvious. If rendered from 3D software according to our specs, there's very little resampling involved. Otherwise (for real world setups, video source etc.), the solution is oversampling.

We do different kind of previews and analysis of frames. Automation is good to a degree, but for now, it involves mainly the expertise and quite complex "feelings" as to what will work, what might work, what is risky etc.. Areas to question: amount of animation, 3d contrast, color contrast, textures, burn, etc.. Not that it will not be printed, but at the price, we want to make it as good as it could possibly be... so sometimes, the test or two are needed to make it perfect, depending on the novelty..

holo_cyware · Post by **holo_cyware** » Sat Dec 26, 2009 9:30 am

Do you use LCD's?

Nowadays LCD's have a much smaller pixel than 0.8 mm.

MfA · Post by **MfA** » Sat Dec 26, 2009 12:47 pm

holo_cyware wrote:Vertical paralax it's certainly possble as i've seen it, but it requires tremendous time for printing the "holopixels" (hours).

Why exactly? I assume the rabbithole printers use the method which records a hemisphere hologram per pel with a single shot of a SLM? (DLP or LCOS most likely, since they use laser light so much more economically than LCDs.) The only thing which should change is the computation time right? Which with todays storage and transfer technologies don't need to be done online.

Now if done independently rendering the pels is going to be a problem even offline, it's equivalent to rendering a movie 100s of hours long ... I suspect there should be some elegant way of calculating the pel hemisphere maps far faster than independent rendering though.

DigiFlash · Post by **DigiFlash** » Sat Dec 26, 2009 4:53 pm

Regarding the LCD and pixel size:

LCD defines angular resolution, so, putting the information with changing image vertically would make full parallax, if the info is made of column of same pixels - that would make horizontal only parallax. But it has nothing to do with holographic pixel size, it defines how this pixel appears from different angles.
This is also the reason why printing full parallax takes the same time as single parallax.

Not sure what you refer to with Online/Offline, but we do transfer all the files from clients by internet, e.g. FTP.
As for rendering, it takes anywhere from several hours to several weeks to render full sequence ~1000 frames to be printed.
And then it takes up to 8h for big holograms to transfer, depends on mutual connection speed.
For full parallax, of course, the rendering time and transfer time go up...

We still do use LCD, not LCOS or DLP. Historically.
Not sure if DLP can be used for pulsed lasers, after all, they get grayscales by time dithering...

Rendering on the fly (while printing) is probably best approach these days, when Graphical processors can do miracles, but this approach is quite limited in it's application and workflow. First, I would imagine, the model should be simple enough to allow this kind of rendering, and second, all kinds of tricks, such as compositing, post-processing etc. would be obsolete which would limit the possibilities to even narrower niche (did I hear Zebra?).