
A better way to make holograms - sohkamyung
https://www.economist.com/news/science-and-technology/21725760-copying-butterflies-wings-better-way-make-holograms
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will_brown
>Instead of the laser, Dr Menon starts with multiple images, taken from
different directions, of the object to be holographed.

I don't think it's a hologram if it's not created with a laser.

But semantics aside I think there are some practical points not addressed by
the article:

1\. A hologram created by a laser is capturing the light field of the object
and so real holograms can be later viewed under microscope and contain said
microscopic detail

2\. If you split a real hologram in half both half will contain the whole
hologram, and continue cutting the hologram into pieces and each piece will
contain the whole hologram from the perspective of the viewing angle of the
piece

3\. Finally the article said laser holograms require a laser to see the image,
but that's only true of transmission holograms (laser hits object then
emulsion). Reflective holograms (laser hits emulsion then object) are viewable
in white light without need for a laser.

I just started studying and creating holograms, and my goals would be: a).
Bring holography out of the dark room (which this does but without the laser);
and b.) develop the first laser hologram video

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Mister_X
FYI, LASER's are not needed to make a Hologram. Dennis Gabor's original
discovery of holography occurred years before Lasers, and was based on
monochromatic sodium or mercury light passed through a pinhole... From:
[http://amasci.com/amateur/holo3.html](http://amasci.com/amateur/holo3.html)

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mhalle
But Gabor's holograms were not display holograms of the type we think of. The
long coherence length of the laser was essential to display holography as
pioneered by Leith and Upatnieks at University of Michigan in the mid 1960s.

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mhalle
Submitted article extremely light on details, and conflates the researcher's
incremental improvements in holography with long established techniques such
as holographic stereograms.

See actual paper for better signal to noise:

[https://www.nature.com/articles/s41598-017-06229-5](https://www.nature.com/articles/s41598-017-06229-5)

And no, we aren't any closer to virtual 3D objects in free space, no matter
what the Economist says. Physics.

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jcl
Reminds me a bit of the "caustic design" papers in recent SIGGRAPHs in that
they're both optimizing a lens's shape so that it produces a particular output
lightfield -- although the hologram needs to incorporate diffraction and
produce a much more constrained lightfield.

(Caustic video:
[https://www.youtube.com/watch?v=R00IvqcI9jU&feature=youtu.be...](https://www.youtube.com/watch?v=R00IvqcI9jU&feature=youtu.be&t=36)
)

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supergreg
Dead butterflies

~~~
yorwba
Context:
[https://news.ycombinator.com/item?id=14460013](https://news.ycombinator.com/item?id=14460013)

Can't unsee it now.

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cypher303
The author used the word "quotidian"... I hope they feel better now.

~~~
todd8
... but I love the sound of that word, I wish I could use it _every day_ ,
LOL.

