Making holograms with a pen plotter
169 points by DemiGuru 17 hours ago | 17 comments
dejobaan 17 hours ago
This is "old Internet" style fun territory (along the same lines as the Tom7 fun, if not quite as deep). I felt that the olive oil + fingerprint + phone screen was a really nice way to illustrate the core concept. Especially clever because it used something common and annoying to help describe how the plotter does its thing.
replyradarsat1 14 hours ago
Before getting further into the article I thought maybe he was going to show how to use the plotter to control the oil smearing technique, which honestly would have been kind of cool.
replyTacticalCoder 16 hours ago
There are very few TFAs I upvotes before opening TFA. But with such a title, this is one of them...
replyauscad 6 hours ago
Holography is such a beautiful and fascinating gateway to physics, and it’s so rare to see true demonstrations of it. Sadly, most people have no idea what it is because of how carelessly the term is thrown around, just like in this article. At least the author admits it and provides some kind of excuse, even if it’s at the end.
replynomel 17 hours ago
Related, "abrasion holography", with great good success for being hand drawn: http://amasci.com/amateur/holo1.html (1995)
replyMaybe could swap out the pen for a needle?
asalahli 15 hours ago
Steve Mould has a great video on youtube explaining how they work https://www.youtube.com/watch?v=sv-38lwV6vc
replyfemto 13 hours ago
It would be interesting to augment the plotter with a Unimorph piezoelectric disk scanner [1], to enable finer movement so lines can be drawn closer together.
reply[1] https://john-alexander42.github.io/simple-stm-web-page/Disk_...
6510 8 hours ago
William Beaty had a video of the hands on the car hood. They showed up very detailed some 20 cm under the hood as if people captured inside. Quite the find.
reply
He uses the third dimension to encode time, so that you get an image of the brain that illustrates how signals propagate dynamically between brain regions.
I have a version of this on my wall and its mesmerizing to look at with the right lighting conditions