

Bullet Impacts at 1,000,000 fps - ax0n
http://blog.makezine.com/archive/2009/10/bullet_impacts_at_1000000_frames_pe.html

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mahmud
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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tomjen2
<a
href="[http://www.reddit.com/r/IAMA>Please](http://www.reddit.com/r/IAMA>Please)
go here and tell your story</a>

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jws
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.

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gzn
5:50 looks like ballistic gel.

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

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Nwallins
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.

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moe
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.

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electromagnetic
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).

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swombat
_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.

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wallflower
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...](http://www.infosyncworld.com/reviews/digital-
cameras/casio-exilim-ex-fh20/9869.html)

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MikeCapone
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?

~~~
enneff
<http://kurzzeit.com/kameras.htm>

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MikeCapone
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...

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mikeytown2
Where can I buy all this footage, not watermarked? Would be cool as a
background video for larger parties.

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ax0n
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.

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jacquesm
here is the camera used:

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

And it's newer brother:

[http://www.shimadzu.com/products/test/hsvc/oh80jt0000001d6t....](http://www.shimadzu.com/products/test/hsvc/oh80jt0000001d6t.html)

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

