Bullet Impacts at 1,000,000 fps | Hacker News Reader

Bullet Impacts at 1,000,000 fps

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81 pointsax0n19 comments

Ugh. As someone still carrying a shrapnel in his leg, I hope none of you come to experience it. I didn't feel it at first, the sound scared more more, but when I saw my leg I could taste bitter metal in my mouth. I was 10 years old :-(

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Youtube video: direct link... http://www.youtube.com/watch?v=QfDoQwIAaXg

The watermarked website is a wreck.

More than just bullet impacts. At around 2:00 I think it is showing a BB sized object hitting a bullet from a perpendicular trajectory. At around 3:00 there is some nice bullet into bulletproof glass action. 5:50 has shockwave formation in liquids.

Back of envelope calculations suggest that most of this is at less than 1,000,000 frames per second, but the slowest of the slow might be at a million.

5:50 looks like ballistic gel.

From 0:00 to 9:59 the video is awesome.

Confirmed on the ballistic gel -- I initially thought it was ice.

> Watch for the hollow point rounds in the ballistics gel.

... from the YouTube summary.

I hate how the clips almost always cut off a second early. For example I really wanted to see how that bullet exits the Gel and how the gel retracts then.

But oh well, amazing video nonetheless.

I remember watching an episode of Myth Busters where they put a block of ballistic gel into a swimming pool and shot at it from everything between a Civil War pistol to a .50cal

Very cool to learn that the slow the FPS of the round, the further into the water it will penetrate.

http://www.youtube.com/watch?v=AUSo6ehRCHI&feature=relat... is 10k FPS, so I suspect the shots of the bullet deforming at ~7min is probably close to 1mil FPS.

It appears as though the impacts that just barely puncture the metal actually do the most damage to the object, which I've always read and been told but never been able to visualize why.

It appears that when a bullet punctures the object easily, it conforms very closely to Newton's Impact Depth approximation, however when it barely makes it through it doesn't appear to conform as one of the impacts appears to make a V-shaped wedge through the metal, similar to a hollow-point impact.

It's very interesting to see impact theory when largely it's a science of math and results, it's rare to see the actual impacts (real impacts, IMO shooting fruit on 10,000 fps doesn't count).

It appears as though the impacts that just barely puncture the metal actually do the most damage to the object, which I've always read and been told but never been able to visualize why.

Think of the bullet as a packet of kinetic energy. When the bullet goes through, most of the energy goes through with it. Therefore, the damage to the object is relatively minimal (just a whole).

When it is stopped, however, pretty much all the kinetic energy needs to be dispersed in the object itself. That happens via a number of mechanisms: deformation of the bullet, deformation of the surrounding material, heat, and, if the bullet breaks into pieces, of course, they can each take a chunk of energy with them as they go shooting in every direction.

I had a Pavlovian response to the Canon EX-FH20 when it was announced late last year.

"The 1000fps videos are 224 by 56 pixels, which, on our screens, is slightly larger than a stick of Trident. For liliputians, this is more than enough resolution. But for the rest of the macro world, a 1000fps video clip from the Casio Exilim EX-FH20 is useful as a novelty act, and that's about it. The 210fps clips are 480 by 360, which looks like a movie theater screen after viewing the tiny 1000fps clips. Regardless, the high-speed videos are fun to play with, as you can see in our samples in the Image Quality section below."

http://www.infosyncworld.com/reviews/digital-cameras/casio-e...

Anyone knows how you get that kind of framerate?

Obvious you're probably not shooting very long to limit the amount of data, but it still must be quite a lot. What kind of buffer do you need?

http://kurzzeit.com/kameras.htm

Thanks :)

I guess I trained myself over the years to ignore watermarks in videos. Usually a good thing, but this time it would've been useful to look...

Not the camera they shot this with but still cool. Phantom V12: http://www.visionresearch.com/index.cfm?sector=htm/files&...

According to the specs you can buy it with 8, 16, or 32 GB of RAM for buffering. It then transfers the buffer either to a PC via gigabit ethernet or to one of these bad boys: http://www.visionresearch.com/index.cfm?page=cinemag&sec...

Where can I buy all this footage, not watermarked? Would be cool as a background video for larger parties.

There are BBs, lead .144 (.22?) wadcutter pellets and what appears to be bird shot as well. It also looks like some of the shots were through rather unconventional media... like ice, perhaps. I enjoyed it.

I thought this was "Bullet Impacts at 1,000,000 feet per second". Frames per second is still cool though.

here is the camera used:

http://www.kurzzeit.com/kameras.htm

And it's newer brother:

http://www.shimadzu.com/products/test/hsvc/oh80jt0000001d6t....

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