The triggering scheme is completely brilliant. One of those cases where not knowing too much made it possible, because someone who does analog debug would never do that (because they would have a 50k$ scope!.
A laser pointer at 2B FPS [video]
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Re: A laser pointer at 2B FPS [video]
#22The triggering scheme is completely brilliant. One of those cases where not knowing too much made it possible, because someone who does analog debug would never do that (because they would have a 50k$ scope!.
Does anyone have a $50,000 scope they could just give to this dude? He seems like he would make great use of it.
Re: A laser pointer at 2B FPS [video]
#23Ah, two billion. The first several times I saw this it looked like "twenty eight", which didn't seem terribly interesting.
The video is definitely more interesting than 28 fps but it's also not really 2B fps.
It captures two billion pixels per second. Essentially he captures the same scene several times (presumably 921,600 times to form a full 720 picture), watching a single pixel at a time, and composite all the captures together for form frames.
I suppose that for entirely deterministic and repeatable scenes, where you also don't care too much about noise and if you have infinite time on your hands to capture 1ms of footage, then yes you can effectively visualize 2B frames per second! But not capture.
Re: A laser pointer at 2B FPS [video]
#24As I understand it, this is sort of simulating what it would be like to capture this, by recreating the laser pulse and capturing different phases of it each time, then assembling them; so what is represented in the final composite is not a single pulse of the laser beam. Would an upgraded version of this that was actually capable of capturing the progress of a single laser pulse through the smoke be a way of getting…
No, as he explains in the video, this is not a stroboscopic technique, the camera _does_ capture at 2 billion fps. But it is only a single pixel! He actually scans the scene horizontally then vertically and sends a pulse then captures pixel by pixel.
Re: A laser pointer at 2B FPS [video]
#25The original MIT video from 2011: "Visualizing video at the speed of light — one trillion frames per second" https://youtu.be/EtsXgODHMWk (project site: https://web.media.mit.edu/~raskar/trillionfps/)
He mentions this as the inspiration in his previous video (https://youtu.be/IaXdSGkh8Ww).
Re: A laser pointer at 2B FPS [video]
#26Ah, two billion. The first several times I saw this it looked like "twenty eight", which didn't seem terribly interesting.
The video is definitely more interesting than 28 fps but it's also not really 2B fps. It captures two billion pixels per second. Essentially he captures the same scene several times (presumably 921,600 times to form a full 720 picture), watching a single pixel at a time, and composite all the captures together for form frames. I suppose that for entirely deterministic and repeatable scenes, where you also don't care…
Nah, it's definitely 2B fps, the frames are just 1x1 wide and a lot of the interesting output comes from the careful synchronization, camera pointing, and compositing of nearly a million 1x1 videos of effectively identical events.
And there are 1 million milliseconds every ~15 minutes. It doesn't take that long to capture all the angles you need so long as you have an automated setup for recreating the scene you are videoing.
Re: A laser pointer at 2B FPS [video]
#27Did he actually repeat the experiment 1280x720 times for every pixel?
Re: A laser pointer at 2B FPS [video]
#28Ah, two billion. The first several times I saw this it looked like "twenty eight", which didn't seem terribly interesting.
The video is definitely more interesting than 28 fps but it's also not really 2B fps. It captures two billion pixels per second. Essentially he captures the same scene several times (presumably 921,600 times to form a full 720 picture), watching a single pixel at a time, and composite all the captures together for form frames. I suppose that for entirely deterministic and repeatable scenes, where you also don't care…
Each pixel was captured at 2 billion frames per second, even if techinically they were separate events. Why not call it (FPS / pixels) frames per second?
Re: A laser pointer at 2B FPS [video]
#29Did he actually repeat the experiment 1280x720 times for every pixel?
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...
Re: A laser pointer at 2B FPS [video]
#30Earlier quoted context omitted.
Who detonated 2073600 bombs?
They did the way more expensive version briefly mentioned towards the start of the video, having 12+ cameras with ridiculously fast shutters (as low as 10 nanoseconds) arranged to run in seqeunce.
That was probably not the more expensive version in that case.