Browsing Tag: high speed camera

    Ultra High Speed Cameras – How do you film a tank shell in flight or a Nuclear bomb test?
    Articles, Blog

    Ultra High Speed Cameras – How do you film a tank shell in flight or a Nuclear bomb test?

    August 15, 2019


    In my last video I looked railguns, now
    whilst I was reviewing the footage I started wondering how they filmed the
    projectiles in flight. These are not the typical sort of high-speed camera shots
    where you see a bullet hitting a target for example, these are tracking the
    projectile from the barrel down the firing range. From the footage it looks
    like the camera is panning around and following the projectile but that would
    be impossible, the tank round is traveling at over 1,500 meters per
    second and would normally look like this. For all of you out there who said it’s
    done with mirrors then you are absolutely correct.
    It works by having a computer-controlled high-speed rotating mirror in line of
    sight of a high-speed camera. The speed of the rotation of a mirror matches that
    of the object being followed so the faster the object is traveling like a
    railgun projectile the faster the mirror would turn to keep up with it. Using this
    method the object can be kept in the field of view for a hundred meters or so
    or about ninety degrees of the mirrors movement. In this example the tracker 2
    from specialized imaging you can see the mirror and to its left where the camera
    is. Because the mirror is computer-controlled it can be programmed
    to follow objects that accelerate even linearly or non linearly. Now rotating
    mirrors aren’t new in fact they were some of the first high-speed cameras and
    are still some of the fastest in the world capable of up to 25 million frames
    per second and were used to record atom bomb blasts. During the Manhattan Project to develop the first atomic bomb they required cameras that could record the
    first few microseconds of explosion. In order to create a nuclear chain reaction
    and achieve critical mass a baseball-sized piece of plutonium had to
    be compressed to about half its size. This was achieved by using an array of
    focused high explosive lenses surrounding the plutonium core. In order
    to make it work effectively the explosives 32 of them in all had to be
    triggered within one microsecond, if any were delayed then the compression
    of the core would be unequal and the reaction would even be much less or may
    not even happen at all. Using a super high-speed camera it will
    be possible to see how effective the explosive lenses had been just a few
    microseconds after detonation. At the time the fastest cameras were Fastax
    cine cameras and could achieve around 10,000 frames per second or one frame
    per hundred microseconds, this still wasn’t fast enough though. The first
    high-speed rotating mirror camera was the Marley, invented by of a British
    physicist William Gregory Marley, the Marley camera used a rotating mirror an
    array of lenses inside a curved housing each focused onto a single piece of film
    around the edge of the case. This could record a sequence of up to 50 images
    onto 35 millimeter film at a 100,000 frames per second. But by the
    time of a Trinity test it was outdated and too slow to record the ultra quick
    reaction in the plutonium core. Head of the photography unit Julian Mack said that
    the fixed short focus and low quality of the lenses would probably have made the
    Marley camera pictures useless. He helped develop the Mack Streak camera
    which had a 10 million frames per second limit, thats one frame every hundred
    nanoseconds. By the 1950s Harold Edgerton had developed the Rapatronic camera
    the name coming from Rapid Action Electronic this used a magneto-optic
    shutter which allowed it to have an exposure time as short as 10 nanoseconds
    thats ten billionths of a second. This was first used with a hydrogen bomb test of
    Eniwetok Atoll in 1952. However they only took one image so to
    see the first few microseconds of a nuclear detonation up to 10 were used
    in sequence with an average exposure time of three microseconds. The images
    were then played back and blended together to give the impression of a
    film. For the British nuclear tests the Atomic Weapons Research
    Establishment created for C4, a huge rotating mirror camera weighing in at
    around 2,000 kilograms and was the fastest in
    the world at the time. This could record up to 7 million frames per second who
    have a mirror rotating up to 300,000 revolutions per minute and recorded the
    first British atom bomb test on the 3rd of October 1952. The rotating mirror
    cameras are still in use today but now they use highly sensitive CCDs
    to replace the filmstrip. The Brandaris 128 and Cordin model 510 have 128 CCD’s and a gas driven turbine mirror driven by helium to achieve up to 25
    million frames per second at a resolution of 500 x 292 pixels for the
    brand iris and 616 x 920 pixels of recording. At 25 million
    frames per second the mirror itself is running at 1.2 million
    revolutions per minute that’s 20,000 revolutions per second so fast of the
    atmosphere inside the camera is 98% helium to reduce for friction and the
    pressure waves that would occur in normal air. And so onto something I think
    you may find rather interesting. It’s not the fastest camera in the world but this
    one is or it was at the time in 2013 the fastest real-time tracker of a moving
    object and was developed by the Ishikawa Oku Lab at the University of Tokyo. Here
    it is tracking a ping pong ball and keeping it in the center of a frame all
    times both during a game and when it is being spun around on a piece of string.
    It does this by moving two mirrors in front of the camera one for the X
    movement and Yvon for the Y movement it then uses software similar to face
    tracking software to provide feedback to control the mirrors with a response time
    of just one millisecond. It can also be used to control a projector and in this
    scene it’s projecting an image onto the ping-pong ball whilst it’s been bounced
    on the bat, you can see the little face change on the ball at the top of its
    travel. So anyways I hope you enjoyed this look at some of the equipment behind some of the most amazing footage recorded to date
    these aren’t the fastest cameras in the world now but it’s still amazing to
    think what can be achieved by mechanical means. So as always thanks for watching
    and don’t forget we also have the curious droid Facebook page and I would
    also like to thank all of our patrons for their ongoing support and if you
    would like to support us then you can find out more on the link now showing so
    thanks again for watching and please subscribe, rate and share.

    Massive Explosive Chain Reaction at 200,000fps – The Slow Mo Guys
    Articles, Blog

    Massive Explosive Chain Reaction at 200,000fps – The Slow Mo Guys

    August 15, 2019


    G: Hello, I’m Gav.
    D: I’m Dan. G: We’re the slow mo guys and today
    we are without lab coats. D: Well, we got these lovely things instead.
    G: It’s true. We’ll start without our phones So there’s no microphones, but hopefully that one’s doing alright We’re here at the Colorado School of Mines and what are we going to be doing, Daniel? D: Well, when you’re mining you need to use explosives a lot of the time. So that’s what we’re gonna be doing, we’re gonna be using explosives. G: It’s quicker than a shovel…
    D: Exactly, except for instead of using it for mining, we’re gonna be using it for slow mo guys purposes G: Yeah.
    D: Which involves a toilet, a safe, some mannequins…
    G: Some mannequins are going to bite it. D: plenty of explosives G: We also have an absolute myriad of phantoms to get absolute range of resolution and frame rates. So let’s have a blast Because of the puns and stuff D: I’ve destroyed a few bogs in my time.
    G: You do like your spicy food.
    D: It’s true. But now we’re literally going to destroy a bog. Okay. All right. This is pretty savage. So we’re gonna have det cord coming around and up into the system which is going to be full of petrol and then the detonation train will go down here into this five pound booster charge of high explosives which is going to detonate and cause a shock wave and hopefully destroy the bog.
    G: So you’ve taken care of all the explosive putting and over here, in this giant metal protective box, we’ve got two Phantom v2512. This one is set to 28.500 frames a second. This one is set to 207.000 frames a second. So it’s very low resolution. But very very fast. Also up there in that yellow box we’ve got a v2640, which will be HD about 12 000 frames a second. (explosion sound) All right, let’s watch that back. Oh!
    D: Oh wow! G: This– where’s the toilet?
    D: It’s just disappeared G: I didn’t see a single piece. D: Not one piece, man. I just saw a big white bright flash. It was so bright. G: Maybe it went out the back? (explosion sound)
    Both: Whoa! G: And all of this white cloud here is all petrol. D: So did we not see it from the other angle because the cloud covered it and now we’re seeing the viable bit? G: Yeah, I think or maybe it just went up. Look. It’ll light up out It looks cool.
    D: Look all this. All of that is lighting up now. Look at it expand. G: Oh man, so scary. Tell you what, the dynamic range on this camera is not bad. Like it’s pretty much held all of those highlights, even though we’re such a higher ISO. D: You know it’s also really cool as often you don’t see a big flaming explosion with rubble going everywhere. It’s just a flame explosion. D: Whereas this…
    G: Toilet-y shrapnel. Well, that’s where the toilet was. D: It’s– I think– There’s no pieces of it left. It’s literally dust. It has been entirely eviscerated. It’s dug a… pretty much a crater and cleared the area of stones completely. G: So this what’s up there with those guys? D: Wow! I’m touching it. Cheers for that. G: Next experiment.
    D: This is the beefiest safe we could find for 150 dollars. I think it’s about 150 years old as well. G: I love how we paid 150$ for a safe that doesn’t work. D: We’re just trying to get into the safe, like if you imagine if you’re a bank robber, we’re gonna try and just blow a hole through the door. G: Yeah, this safe seems to have lost most of its concrete. But we’ve got this barrel here to see. Hopefully, we’ll see it come into there. D: Yeah. So what I’ve got here is a shaped charge. It looks funny because it’s got a copper cone inside and packed in behind the copper cone is explosives. This is the det cord. It’s what we use to initiate it. So explosion will come down the det cord, down here, hit the back of the shape charge and the explosive explosion the detonation will start at the back and travel forwards. What that’ll do is force this copper cone into an inverse jet so it will– the back part here, right the back, will come out here before this part even gets it and it will form a jet and that’s used to penetrate things like tanks armor or safes or anything like that and the correct– you have to have something called standoff and that’s six times the diameter of the cone which means that that’s about 23–24cm away from what you’re going to penetrate because that’s the width. The width is about 4cm. G: So if you had it too close, it wouldn’t be as effective. D: It wouldn’t be as efficient. The copper jet wouldn’t have reached peak, like, penetration capability. (explosion sound) G: I’ve never seen a shape charge in slo-mo.
    D: Neither have I actually, not properly. ‘Cause they’re usually a part of– Both: Wow!
    D: What?! G: That was absolutely instant.
    D: Whaat G: All right, wind that back, hold on. It’s honestly like when a meteor enters the atmosphere and you’re watching a big ball of light coming through the air. D: It’s the same sort of speed as well, I feel like. G: The cup has already gone into the water And then when we spin on you’ll see that miles later the barrel comes up D: Oh, I just love how directional this explosive is. and that’s what it does. It’s its job. G: Literally nothing went anywhere else. D: Oh, perfect, look at that! Hang on. So it went into the barrel but it didn’t come out the other side, which means there must be some copper at the bottom. But it’s annihilated all the concrete around it it’s like you see all this concrete here yeah that was in the safe and I know we say this a lot. But like it’s nothing. It’s just a skew solid Mel So all of the shaped charges I’ve used before in the military have been solid copper lining Yeah, whereas this is an oil and gas shaped charge and it’s actually made of copper powder. So there won’t be any Solid bits of copper anywhere and you can see here. That’s what that is. Yes. That’s what that is That’s a smattering of copper powder. And before when you ones that are used against tanks and things you can actually see the copper That’s left over in the hole that makes because it’s solid copper. So we’ve got Doris and Frank here, who are Retired mannequins. Well, I’ve noticed that Doris’s fingers come off. Yeah, that’s why she was retired to shed an industrial accident This is a shock tube. Yeah and has inside it’s called a dust explosion which travels down the tube and 2,000 meters a second and that’s enough to initiate a detonator Which is then enough to initiate det cord which is what it’s used for But what we’re going to do is trail it all the way from where we are All the way down swirling around it’s going to come to doris here. We’re going to wrap it all the way around doris Like this down to the bottom where we’re going to hit a detonator Into some det cord which is then going to wrap all the way back around her around her here And then that will actually explode and hopefully sort of obliterate because this is just sort of quite safe It won’t do anything to her and then the det cord this is quite long It’s gonna travel from a neck all the way down to here where we’re gonna have a shaped charge Which is then gonna go through what’s his name Frank through Frank? Yes, Frank through Frank and then we’ve got some foam casters on the other side that all hopefully explode when the Copper jet manages to go through so this is a huge chain reaction of a bunch of different types of explosives It’s a explosive train is what it’s called. So you start small with something like this Yeah, you’re going to prime explosives with detonator and then into det cord and then it will main charge so this time I’m going to Set the exposure on the Phantom’s much lower so we don’t get as much white out from the det cord explosions get more detail. Yeah Look up her skirt. I was looking into my finger Look up her skirt from here down. This is a special occasion yeah, because we’ve got a return of a very rare guest the slimmer guys its other Dancer its rival dads. This is a little bit of an awkward situation having both of us here at the same time You may not recognize down because in this video he has a shirt on finds Explosives in bare chest just doesn’t work out. So then this one here will be the edge we Start from that will go up the stairs. See this little symbol here That’s where we’re gonna pop the det cord in that little cradle Yeah, so it’s enough explosive force to initiate the shape charge which is gonna last its way through Frank. This is an absolute operation It’s just raw nerve record to watch your det cord on your head Basically, I mean it’s perfectly saying you can chew it and it wouldn’t do anything. I Have taste earlier. It’s called secondary explosive Fare to be second. Sorry, I think so. That’s the shot right there Quick it looks fake, isn’t it? It’s gonna be like a little disco happening in Most dangerous nightclub ever Do you think the the det cord because it was wrapped so tight around the head it all just went at once around the head Yes Sympathetic detonation. So yeah, one of the layers would have got the next one The shape charge beats the shockwave, yeah, it’s insane I Deliberately made this one much much darker because we’re sure and much much slower But we should actually see the shop tube travel almost a leisurely pace at this frame rate. Oh Here we go. It’s gone down the legs waiting come in. Any second. Oh, where are we? Oh, here we go. I think it’s just The step up in speed is so insane Whoo, because you see the shock tube going only 2,000 meters a second, but the det cord is then going at 7,000 It’s a huge step up and that shaped charge that looks like a damn rocket going off that’s getting about 10,000 meters a second and when you were describing the shape charge, I thought it would be more like a shotgun We’re just kind of blow all in one direction But it’s so narrow and so specific like you could you could shoot someone with it Yeah, the field you could shoot it right at someone and it might miss it’s like a neat it’s like an explosive needle Well, there’s a hand, oh was that good hand. Oh That’s a shame. She’s had a hell of a retirement by there looking what’s done to address the debt course just like Crisped it up d dressed. Look what the shape charged it to this guy it completely sawn him in half Oh, Totally honestly when I saw him in half here, I thought that this part had just come off Yes same but then I thought you’re connected. Actually, it’s still connect. This is just loose. Oh He’s just taking him in half is all the phone that caught fire Didn’t actually get the other one look didn’t get that one. It just completely blew his front out his front fell off his To get Doris his head to fall off by wrapping it in det cord and it I saw it from over there Pop up about 30 40 feet and then it landed One of her eye sockets on oh no. Oh it’s Gruesomes a splintered sever. You should keep that the head yeah Use it as like a I mean surely though if I try and take it home when they try and swab it, they’ll be like I Think there’s a small amount of explosives there. So you just say to TSA just like well, yeah it blew up blew off obviously You using this as an another opportunity to blow up some of our merch yeah, all right, oh It’s a woman blow it out. Oh dear. This is a nice t-shirt, right? This you’re kidding All right looks that was good what you think yes lovely so we’ve made what can only be described as a monstrosity or some sort of secret weapon Let me talk you through this We’ve got an avalanche er easy used to fire into avalanches into a snow story to force an avalanche So it’s not dangerous. Yeah that leads down into this huge fat tube, which reaches all the way down to the floor, which is filled full of ammonium nitrate fuel oil Granular they look like what you feel a beanbag with except they explode. That’s exactly what looks and then round behind it You’ve got to five pound boosters this is all connected with about six foot of det cord so it’s about 50 or more pounds of Explosive – we also put a third mannequin up the back. Yeah We took her back there just to see if what the effects were Compared to obviously this guy’s gonna get a victory and I think that one’s probably not gonna see much though. I’ll see you there I wonder how much would be left. All right, let’s get the hell out of it Trevor how this place used to look before we did that experiment. Oh It’s just like it’s been a hurricane Shot to hang onto the ground in the hole of Thoreau guys, that’s never have the first I hope so Oh well back there it looked like a new it was so bright initially you can see Anything like how would you expose for that initial explosion? You could do it but you’d have to you probably wouldn’t see anything. You just see nothing to start with. Oh That looks like the end of the world oh oh just like a sparks sparks and flashes from the or it’s usually the rock or maybe just fast-moving plastic fast enough where it’s actually igniting on him It honestly looks like that was fired from a fat man. It does it looks like And then once did you see the shockwave go up you see it moving across all this floor back here See he’s got up there and then it’s lifting up all of the dirt and now it’s imploding back down Camera hammer yet that might be one of the best and most well-defined shockwaves I’ve ever seen It looks like a pyroclastic flow from her from a volcano, it’s just water Yeah, and then through the window but bash the camera out I can’t think of any time that I would have seen any explosion that was that big that close I’ve certainly never seen anything like that Explosion camera shelter. I feel like they’ve never done an explosion this big here. I think no, that’s why you’re like they definitely know Hey get bigger It’s blowing it in a like cripple their front ways it was there and it shoved it ripped it like a tin can What is interesting is that it shocked mud so far, like look at our old barrel with a hole in look at where that was Glad to see that even here You would have an absolutely murdered by that so the 26:40, which was up on the hill is it also got caked in one? I went out there what how quickly the mud caked the the view of the camera there Oh But such a wide lens on it This is the left hand mannequin that was here it was previously about here. That was the one that wasn’t the closest Yeah, and he’s turned to paste. I honestly don’t know if we could show this is a bit graphic This lady was stood here About five six meters away. Yeah, she got picked up by the explosion but another four meters back The legs off both her arms are off It’s just shows the massive amount of difference between evisceration a couple bits left and then like, you know Most of it left. I can’t believe it blew in our safety this because he put the charge behind the water that’s the that’s a thing in in a OD you is called a disrupter you place explosive charges behind water and it basically just Messes up everything that’s in front of the water really quickly. So he’s placed the charge behind the water in the waters just gone straight into the camera shutter, and that’s what’s done that Lets try and find a piece of your slow mo guys shirt Pull that out. That’s great Look at that It’s the RoosterTeeth thing. …Erteeth Oh no it’s “Terteeth” “Terteeth” “Terteeth” Euh “Terteeth” Well Do you know what my least favorite part of every Slo Mo video’s? What’s that? Well part for me being hurt. Yeah Is cleaning up afterwards. But all we’ve left today is a smoking crater. What and there’s like pits of genes That’s chicken stuff H. There’s no plastic It’s just biodegradable G that might be one of the most mental videos we’ve ever made. It’s insane That was that’s a lot of explosives. Yeah, well Big thanks to Vision Research for setting this up and letting us use their phantoms an extremely dangerous Environment and thanks to the Colorado School of Mines filling us come and blow stuff up here. Hopefully you enjoyed that video Feel free to follow us on social media and stuff subscribe to the slow mo guys, and we got a second channel We’ll see you next time Feel like the next video should be really relaxing in comparison Yeah, I think we need something like and I just chill this was yes. This is a lot