[HN Gopher] Specular Holography: How (2010)
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       Specular Holography: How (2010)
        
       Author : matthberg
       Score  : 49 points
       Date   : 2023-07-09 03:49 UTC (19 hours ago)
        
 (HTM) web link (zintaglio.com)
 (TXT) w3m dump (zintaglio.com)
        
       | selimthegrim wrote:
       | Is this not akin to
       | https://www.researchgate.net/publication/231068500_Oriental_...
       | (if the mirror wasn't covered by a polished front?)
        
       | skcgake3 wrote:
       | A page from 1995 about this topic.
       | http://amasci.com/amateur/holo1.html
        
         | carapace wrote:
         | Cheers! That's got to be one of the best pages on the internet.
        
       | jacomyma wrote:
       | Steve Mould's video gives an accessible explanation and good
       | sense of what these objects feel like:
       | https://www.youtube.com/watch?v=sv-38lwV6vc
        
       | Modified3019 wrote:
       | After seeing the "lumographic lens" video
       | (https://www.youtube.com/watch?v=oiDqUkmozlM) I managed to dig up
       | some interesting research on what is basically a method of
       | milling a "lens" to project an image at an arbitrary focal point
       | using light convergence for "white" and divergence for "dark.
       | 
       | https://cdfg.mit.edu/publications/fabricating-microgeometry-...
       | 
       | https://cdfg.mit.edu/publications/goal-based-caustics
       | 
       | https://cs.dartmouth.edu/~wjarosz/publications/papas11goal.m...
       | 
       | https://cdfg.mit.edu/publications/ in general has a considerable
       | amount of interesting publications regarding computational design
       | and fabrication of neat optical effects.
       | 
       | As does
       | https://web.archive.org/web/20140623052716/http://lgg.epfl.c...
       | 
       | >Caustics are captivating light patterns created by materials
       | bundling or diverting light by refraction or reflection. We know
       | caustics as random side effects, appearing, for example, at the
       | bottom of a swimming pool. In this work we show that it is
       | possible to control caustic patterns to form almost any desired
       | shape by optimizing the geometry of the reflective or refractive
       | surface generating the caustic. We demonstrate how this
       | surprising result offers a new perspective on light control and
       | the use of caustics as an inspiring design element. Several
       | produced prototypes illustrate that physical realizations of such
       | optimized geometry are feasible.
       | 
       | Now redirects to https://www.epfl.ch/labs/gcm/publications/
        
       | _Microft wrote:
       | This is light on details if I haven't missed a link to another
       | page or something.
       | 
       | Definitely browse the links to the images in the ,,See:" section
       | of the submitted page though - the images and videos on the knots
       | and nature pages are beautiful!
       | 
       | Maybe there are useful references in the Wikipedia article:
       | 
       | https://en.m.wikipedia.org/wiki/Specular_holography
       | 
       | Edit: maybe this, even though the page is awful to use on mobile:
       | http://amasci.com/amateur/holohint.html
        
         | agumonkey wrote:
         | early dent-oriented shaders
        
       | Nition wrote:
       | When I was a kid in the 90s my parents took me to some sort of
       | art gallery hidden upstairs above other shops, that was doing a
       | hologram exhibition (wavefront holograms, not specular ones like
       | in this article). It was dark inside and they had a whole lot of
       | amazing large format holograms of various things lit up.
       | 
       | I kind of wonder why holograms of all types aren't more popular.
       | It's still amazing to see a 3D image on a 2D plane that you can
       | look at from different angles.
        
         | sbierwagen wrote:
         | I spent ten minutes the other day trying to buy _any_ laser
         | hologram, and as far as I can tell the market just does not
         | exist at all outside of  "call us" pricing for science museums
         | and such. Also doesn't help that the word "hologram" has been
         | watered down to uselessness by competing technologies.
        
           | Nition wrote:
           | Yep exactly, that's my experience as well. And I think the
           | other reply saying it's possible to find them on eBay is kind
           | of missing the point. Anywhere you can buy them is kind of
           | obscure or unofficial.
           | 
           | I don't understand why something so cool, that keeps working
           | forever, is so relatively rare.
           | 
           | I think the only other one I've seen in the wild since that
           | exhibition in the 90s that wasn't some tiny thing, was a Lord
           | Of The Rings one that Weta Workshop had given to a lecturer
           | of mine.
        
           | deanputney wrote:
           | Ten minutes! Wow.
           | 
           | Did you check eBay? There are definitely examples for sale
           | there. Holography-specific groups have hints on where to buy
           | some too. The popular ones are hard to find, but you can make
           | them yourself at home or find less sophisticated pieces for
           | sale occasionally.
        
         | EvanAnderson wrote:
         | This wasn't in Chicago, perchance, was it? There was a lovely
         | museum of holography there that I was lucky enough to visit in
         | the early 2000's before it closed. Your description reminds me
         | of that.
        
           | Nition wrote:
           | No, but that sounds like a place I would have enjoyed.
        
       | speps wrote:
       | Applied Science has some amazing explanation and application of
       | these principles on tempered chocolate:
       | https://youtu.be/UsDnkrDvkBo
        
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