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A laser pointer at 2B FPS [video]

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615 points thunderbong | 1 comments | 19 Oct 25 06:42 UTC | HN request time: 0.2s | source
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avidiax ◴[20 Oct 25 22:41 UTC] No.45650342[source]▶
He did a good job on his setup, but I have to think that adding a spinning mirror would have made everything much faster and easier.

He could then capture an entire line quite quickly, and would only need a 1 dimensional janky mirror setup to handle the other axis. And his resolution in the rotating axis is limited only by how quickly he can pulse the laser.

Of course, his janky mirror setup could have been 2 off-the-shelf galvos, but I guess that isn't as much "content".

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kllrnohj ◴[20 Oct 25 23:20 UTC] No.45650637[source]▶
I think a spinning mirror would make it a lot harder. He's only moving the mirror after the "animation" finishes. So it's capture video, step by 1 pixel, capture video, step by 1 pixel, capture video, etc... He's replaying the scene ~1 million times, for 1 million unique single pixel 2 billion fps videos.
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1. rcxdude ◴[21 Oct 25 12:48 UTC] No.45655106[source]▶
Basically the constantly spinning motor would remove the complexity and slowdown of accelerating and decelerating it at the start and end of the motion. To capture a line, he's already scanning it across the scene and triggering the laser at specific points (when the encoder in the servo reaches certain values), if it was continuously rotating he could just do the same thing.

Though I don't think it would speed things up much, from what he was saying in one of the appendix videos on his second channel he doesn't do things like triggering the laser multiple times for each pixel to reduce noise because the bottleneck is copying the data off of the scope and it would stretch from hours to days to run.