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Many years ago, someone did a similar holographic hack with a spinning hard drive motor, a piece of reflective plexiglass mounted upright on it, and a small pro

by sigil 3y ago

Many years ago, someone did a similar holographic hack with a spinning hard drive motor, a piece of reflective plexiglass mounted upright on it, and a small projector. As the plexiglass carved out a cylinder, the projector sent a series of frames adjusted for each little slice of 3D space. [0] This gave me a wild idea: what if you could encode a low-resolution 3D video on the left channel of a stereo vinyl groove? [1] A special record player with a spinning plexiglass plate could then play holographic albums. The hologram would stay perfectly in sync with the music if you changed speeds or did turntable scratching. [0] If anyone can find a link to the original spinning hard drive hologram project please drop it! [1] I assume this wild idea isn't feasible given vinyl data rates?

gs17 3y ago
There's a low tech version of the vinyl hologram: https://youtu.be/aEbAaL7fPl4 https://youtu.be/aEbAaL7fPl4
- sigil 3y ago
  Different but pretty cool idea!
Someone 3y ago
> assume this wild idea isn't feasible given vinyl data rates? Data rates go up if you spin the disk faster, and can get fast enough for 2D video. I don’t think it was vinyl, but https://en.wikipedia.org/wiki/Television_Electronic_Disc https://en.wikipedia.org/wiki/Television_Electronic_Disc: “Program information was stored in the form of ridges in the surface of a thin, flexible foil disc, which was claimed to be sufficiently robust to withstand being played 1,000 times. The main technological breakthrough was the vertical recording method that reduced the track pitch to 0.007 mm, and increased the rotation speed to 1,500 rpm, making it possible to record 130–150 grooves per millimeter, compared with the typical 10–13 grooves on an audio disc. This increased the available bandwidth from around 15 kHz to 3 MHz.”
- sigil 3y ago
  Amazing, first I've heard of this. Here's footage of someone playing a Television Electronic Disc: https://youtu.be/XkP4ZJnMVOs?si=QbT4EXrE1dpq-Rtz https://youtu.be/XkP4ZJnMVOs?si=QbT4EXrE1dpq-Rtz
fortran77 3y ago
There's no "Left Channel" on a stereo vinyl groove. There's an A+B channel (horizontal) and A-B Channel (vertical). Left and Right are created electronically from these two signals.
- sigil 3y ago
  Right, I forgot this detail. Thanks for the correction.

by sigil 3y ago

gs17 3y ago

There's a low tech version of the vinyl hologram: https://youtu.be/aEbAaL7fPl4 https://youtu.be/aEbAaL7fPl4

sigil 3y ago
Different but pretty cool idea!

Someone 3y ago

> assume this wild idea isn't feasible given vinyl data rates? Data rates go up if you spin the disk faster, and can get fast enough for 2D video. I don’t think it was vinyl, but https://en.wikipedia.org/wiki/Television_Electronic_Disc https://en.wikipedia.org/wiki/Television_Electronic_Disc: “Program information was stored in the form of ridges in the surface of a thin, flexible foil disc, which was claimed to be sufficiently robust to withstand being played 1,000 times. The main technological breakthrough was the vertical recording method that reduced the track pitch to 0.007 mm, and increased the rotation speed to 1,500 rpm, making it possible to record 130–150 grooves per millimeter, compared with the typical 10–13 grooves on an audio disc. This increased the available bandwidth from around 15 kHz to 3 MHz.”

sigil 3y ago
Amazing, first I've heard of this. Here's footage of someone playing a Television Electronic Disc: https://youtu.be/XkP4ZJnMVOs?si=QbT4EXrE1dpq-Rtz https://youtu.be/XkP4ZJnMVOs?si=QbT4EXrE1dpq-Rtz

fortran77 3y ago

There's no "Left Channel" on a stereo vinyl groove. There's an A+B channel (horizontal) and A-B Channel (vertical). Left and Right are created electronically from these two signals.

sigil 3y ago
Right, I forgot this detail. Thanks for the correction.