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A laser pointer at 2B FPS [video]

(www.youtube.com)
615 points thunderbong | 3 comments | 19 Oct 25 06:42 UTC | HN request time: 0s | source
1. brcmthrowaway ◴[21 Oct 25 00:54 UTC] No.45651267[source]▶
Did he actually repeat the experiment 1280x720 times for every pixel?
replies(2): >>45651280 #>>45653033 #
2. gpm ◴[21 Oct 25 00:55 UTC] No.45651280[source]▶
It's pretty clear he had a computer repeat the experiment that many times in reasonably rapid succession rather than doing it "himself", but yes...
3. generuso ◴[21 Oct 25 06:28 UTC] No.45653033[source]▶
Yes, the laser was fired at 3 KHz, while the mirrors were slowly scanning across the room.

For each laser pulse, one microsecond of the received signal was digitized with the sample rate of 2 billion samples per second, producing a vector of light intensity indexed by time.

A large number of vectors were stored, each tagged by the pixel XY coordinates which were read out from the mirror position encoders. In post-processing, this accumulated 3D block of numbers was sliced time-wise into 2D frames, making the sequence of frames for the clip.