Making Holograms with a Pen Plotter
A pen plotter enthusiast discovers how to create holograms by etching reflective ridges into CD jewel cases. Starting from the simple observation of grease smudges on a phone screen, he explains the physics intuitively and shows how to control the apparent motion of highlights to encode depth. After several failed attempts with other materials, he succeeds with old jewel cases, producing surprisingly effective holograms that work with a point light source. The project is a low-cost, DIY approach to holography that anyone can try.
The required tools are so simple that ancient peoples could have drawn these images in hardened sooty resin pools with wooden tools, had they but known the trick.