This is light on details if I haven’t missed a link to another page or something.<p>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!<p>Maybe there are useful references in the Wikipedia article:<p><a href="https://en.m.wikipedia.org/wiki/Specular_holography" rel="nofollow noreferrer">https://en.m.wikipedia.org/wiki/Specular_holography</a><p>Edit: maybe this, even though the page is awful to use on mobile: <a href="http://amasci.com/amateur/holohint.html" rel="nofollow noreferrer">http://amasci.com/amateur/holohint.html</a>
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.<p>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.
Steve Mould's video gives an accessible explanation and good sense of what these objects feel like: <a href="https://www.youtube.com/watch?v=sv-38lwV6vc">https://www.youtube.com/watch?v=sv-38lwV6vc</a>
A page from 1995 about this topic. <a href="http://amasci.com/amateur/holo1.html" rel="nofollow noreferrer">http://amasci.com/amateur/holo1.html</a>
Applied Science has some amazing explanation and application of these principles on tempered chocolate: <a href="https://youtu.be/UsDnkrDvkBo" rel="nofollow noreferrer">https://youtu.be/UsDnkrDvkBo</a>
After seeing the "lumographic lens" video (<a href="https://www.youtube.com/watch?v=oiDqUkmozlM">https://www.youtube.com/watch?v=oiDqUkmozlM</a>) 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.<p><a href="https://cdfg.mit.edu/publications/fabricating-microgeometry-custom-surface-reflectance" rel="nofollow noreferrer">https://cdfg.mit.edu/publications/fabricating-microgeometry-...</a><p><a href="https://cdfg.mit.edu/publications/goal-based-caustics" rel="nofollow noreferrer">https://cdfg.mit.edu/publications/goal-based-caustics</a><p><a href="https://cs.dartmouth.edu/~wjarosz/publications/papas11goal.mp4" rel="nofollow noreferrer">https://cs.dartmouth.edu/~wjarosz/publications/papas11goal.m...</a><p><a href="https://cdfg.mit.edu/publications/" rel="nofollow noreferrer">https://cdfg.mit.edu/publications/</a> in general has a considerable amount of interesting publications regarding computational design and fabrication of neat optical effects.<p>As does
<a href="https://web.archive.org/web/20140623052716/http://lgg.epfl.ch/caustics/" rel="nofollow noreferrer">https://web.archive.org/web/20140623052716/http://lgg.epfl.c...</a><p>>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.<p>Now redirects to <a href="https://www.epfl.ch/labs/gcm/publications/" rel="nofollow noreferrer">https://www.epfl.ch/labs/gcm/publications/</a>
Is this not akin to <a href="https://www.researchgate.net/publication/231068500_Oriental_magic_mirrors_and_the_Laplacian_image" rel="nofollow noreferrer">https://www.researchgate.net/publication/231068500_Oriental_...</a> (if the mirror wasn’t covered by a polished front?)