Welcome to the High-Speed Videography Page!
See sparks fly captured at over 6,800 frames per second!
Normally we see fireworks in the warm summer night sky as objects of unquestionable beauty and fascination - certainly an art form all its own. Now, in the interest of overall safety awareness, pyro science and the continuing effort to design state-of-the-art firing systems, Starflight Electronics is proud to present these videos which show pyrotechnic events as you've never seen them before - Captured with an ultra high speed video camera we can now see details that are just too fast to really see with the unaided eye.
See the launching of a commercial display fireworks shell, an electric match head bursting into flame, and the amount of heat generated by a malfunctioning fireworks shell. These videos reveal another form of the beauty and incredible energy of pyrotechnics - and why all responsible pyro crew personnel treat these devices with the utmost care and respect.
With many thanks for a generous demonstration of the fantastic Redlake model HS-4 high speed video camera (by Jason McGinnis of PSI Solutions, Inc.) Starflight Electronics is proud to offer these interesting pyrotechnic events captured at 5,000 and 6,820 frames per second. Normal film and video cameras operate at 24 and 30 frames per second, so we are "slowing down time" by a factor of over 200 times in these videos.
Capturing these videos is not an easy undertaking, but with materials, ideas and support from Entertainment Fireworks, Inc. (especially Ken Julian, Terri & Gary Schuette, and the rest of the gang at EFI), and with some generous advice on camera housings from John Petrash of Specialty Fireworks in Gleason, WI, we were able to come up with a design for capturing some fantastic video images of what happens "nearly instantly" to the human eye. This is the result of literally days of labor getting the equipment ready, planning the shots for safety of camera and crew, and then waiting for a break in the rainy weather here in Washington State. These shots were taken mostly on March 22, 2005.
This is only the first round of high-speed photography. Later on we hope to add to this collection with a more refined approach to the test setup, so we can see even greater details. For these test video shots, the camera was placed in a heavy protective housing specially designed to protect the camera and the lens, and yet still provide a clear view of the action. Based on these tests, the protective camera box can be redesigned for the next batch of videos.
NOTE: In order to view these videos, your computer must be able to playback Microsoft "wmv" video files. You can get the Windows Media Player for free here. And not the version you downloaded way back in 1997, either. Try to get a fairly recent version - either version 9 or 10 should work OK. And no, there isn't any sound with these, so turn the volume back down. And yes, there is a version of Windows Media Player for Apple users as well. For Linux users there are many player options, "vlc" being one route, but you'll know what works best on your system.
For best performance we recommend that you RIGHT-CLICK the links below and "Save As..." to your computer first, and then play the file directly from your computer's hard drive.
NOTE TO THOSE WITH A LOW-SPEED (TELEPHONE MODEM) CONNECTION: These videos are 4 to 10MB in size, so downloading is going to take some time. If you're limited on download speed probably the best videos to download are #1, #8, #13. If you have kids get #14, which will put everything in perspective for them.
COPYRIGHT NOTICE ( (c) 2005 by Starflight Electronics, all rights reserved. No reproduction permitted by any means without written permission, except for personal, non-commercial use) These images are provided free for your personal viewing, however we ask that you please DO NOT post these files onto other websites, and please leave the credits intact and unchanged. Posting a link to this page is perfectly fine! Thank You!
NOTE: In the videos below, a time index is shown in the upper left hand corner of the video. This indicates the time from when the electric match was fired to initiate the event. In other words, at time 0, the current starts flowing into the electric match.
CLICK ON ANY IMAGE TO ENLARGE
VIDEO ARE COMPRESSED FOR WEB, SO THERE IS SOME LOSS OF CLARITY
1. Normal 3-inch Shell Video This is just a standard 3" Peony shell being fired from a standard mortar at 6,820 frames per second. The scene was shot in direct sunlight with the camera aperture reduced as much as possible so we can see the details of the muzzle blast. The white post visible in all of these mortar firings is marked in 1 foot intervals, with approximately 6' visible from the top of the mortar to the top of the frame. The actual muzzle blast extends to about 8' from the top of the mortar. The shell actually leaves the mortar at about time mark 0.1017 sec, and the distortion you see at about 0.13 to 0.14 sec is the camera housing mirror flexing from the shock wave of the muzzle blast. In all of these mortar shots, the camera housing is about 35 feet from the blast area - and the camera is looking at the scene via an angled mirror, so as to protect the camera as much as possible.
2. Normal 4 inch Shell Video Again, a standard 4" Peony shell being fired from a standard mortar rack. In this case the mortar rack was not sitting perfectly solidly on the ground - there was about a 1" gap at the left end of the rack. You can see the rack bounce slightly, and the electrical firing terminal rail ("slat") get pulled around.
3. Normal "Class C" Shell Video Here you see a perfectly normal "Class C" toy fireworks shell (Like you'd purchase at a retail fireworks stand). Even these 1-3/4" inch shells fired from a small cardboard mortar posses a muzzle blast of considerable energy. We were laughing at this particular little shell - if you look closely, you'll see that the shooting wire never broke during the firing of the shell. This little guy carried its own ematch shooting wire all the way to the top...
4. 3-inch Salute Mortar Detonation Video Here we have every pyrotechnician's worst nightmare: A "salute" shell detonating inside the mortar. Now in this video you can see that a "detonation" happens much faster than the normal shell lifting out of the mortar - and you'll see the camera sensor go dark for a while right around .07 sec. The camera sensor was literally swamped with the brightness of the flash and had to reset itself. Then there is a long patch of "plain old white" which is a combination of fireball and "IR Heat" filling the entire frame. Later on during the video you'll see a chunk of wood moving out of the top of the frame - this was located about 70 feet away, behind the camera. The piece of wood moving towards the lower left of the video land about 30 feet away from the blast. Several test pieces of glass about 6" X 6" were placed at various distances from the blast - the blast broke the glass up to about 15 feet away. An electronic pressure sensor placed about 2' away from the blast registered about 1,000psi the moment before it was destroyed. The remaining "fireball" that exists throughout the video is not all visible flame - it is the infrared heat signature left over from the explosion fireball being picked up by the sensitive camera sensor. Even at several feet from the mortar blast, the heat rise of the surrounding air was into the hundreds of degrees C.
NOTE: Salutes are the shells that you'll see at a fireworks show that ascend and then just explode with that wonderful chest-thumping ka-BOOM and leave your eyes blinking with that bright flash of light. These shells are typically filled with "flash powder" which "detonates" very, very fast. This happens much more quickly than regular "Black Powder" - which doesn't detonate but will "deflagrate" instead. Almost all other fireworks shells will burst open using black powder, and therefore the "boom" you hear is much less loud.
Note: The black spot on the 1/2" plywood backdrop board is a thru-hole formed during this blast. A small piece of the mortar broke off and was sent straight through the plywood at a distance of about 20" from the mortar. Yes, sometimes even HDPE mortars come apart.
5. 4-inch Standard Shell Never Leaves Mortar Video Here we have a typical 4" commercial display shell that explodes inside the mortar, ripping apart everything around the mortar, but leaving most of the rack intact. This can happen due to pyro operator error (loading the shell upside down) or a malfunctioning shell. Again, the giant fireball shown in the video is partially the infrared heat signature of the super-heated gases around the ripped-open mortar. You'll see the viewing mirror flex also, as the shock wave hits it.
6. Typical Electric Match Video #1 Here we have a shot of an electric match (a.k.a. "Ematch") igniting, in this case an Oxral brand of ematch. These electric matches are commonly used at large commercial fireworks shows to ignite shells at exactly the right time - usually controlled by a large manual or computerized firing system. These electric matches are really similar to a regular kitchen match, except a small nichrome wire is placed in the center of the composition. When an electrical current is passed thru the wire, the wire rapidly heats up and the composition is ignited. Normally the ematch is placed into a fuse (or Quickmatch, see below) that leads to a shell lift charge. At the appropriate time during the fireworks show, the ematch is energized, it ignites, which in turn lights the quickmatch fuse leader, which then in turn passes the fire to the shell lift charge and "Boom!" The shell is on its way into the evening sky. But the ematch starts it all.
NOTE: In some of these videos you'll see part of the match head fall away as it is ignited. This is normally not a problem since the ematch is almost always placed tightly inside the quickmatch fuse, which tends to keep the burning composition all held together.
ANOTHER NOTE: In these videos you'll see an LED light that glows at the beginning of the video and then goes out. This LED is wired in series with the ematch, so we can measure not only how long it takes the ematch to ignite, but how long it takes for the nichrome igniter wire to burn out.
YET ANOTHER NOTE: For you technical pyro types, these images were all shot with 24 volts DC, dropped through a 30 Ohm resistor to simulate a wire run or other ematches wired into a series circuit (measured current was .83 amps during the firing pulse). With the exception of video number 6, which was shot with a 20 ohm resistor in series (measure current 1.18 amps), and you'll see that it ignites a little faster than the rest. Otherwise all the ematches shown were fired from an identical firing circuit, with a bit more than the minimum recommended firing current applied for series circuit firing.
7. Typical Electric Match Video #2 In this video you can clearly see the nichrome wire on the ematch just as it is burning out. That's the white glow fading out as the composition ignites and falls away from the match head.
8. Typical Electric Match Video #3 Just a gorgeous shot of an ematch doing exactly what it is supposed to do.
NOTE: In the videos above, notice how the ematch ignites very quickly and reliably. The videos below show what happens when an ematch manufacturer isn't assembling their matches correctly.
9. Asian Import (orange lead wires) Video #1 Here we see a cheaper version of an ematch, that has completely different burn characteristics than the matches shown above. These ematches spend a lot of energy blowing the composition clean off the match head, without doing a lot of burning. In addition, these take quite a long while to ignite compared to the Oxral brand.
10. Asian Import (orange lead wires) Video #2 Again, you get what you pay for in an ematch. A relatively long delay before ignition. Another thing to note: The ignition delay time for these two matches is so different that these matches wouldn't function properly if they were wired in series into the same circuit. If you look closely the match in video #9 takes about 16mSec to ignite, which is about the same time its igniter wire burns out. The match in this video takes about 22mSec to ignite....If these two matches were wired in series, only the ematch in video #9 would probably have ignited and burned out before this match would have a chance to ignite.
11. Quickmatch - Chinese Flat Shell Leader Video Here is a shot of what is commonly called "Quickmatch" in the pyrotechnics industry. Typically this is 5 or 7 strands of black-powder impregnated cotton string enclosed in a simple paper casing. This is sometimes called a "fuse" but it isn't meant to burn slowly - this stuff is designed to transfer fire as rapidly as possible from "Point A" to "Point B". A single shell will use a section of this "Leader" the get the fire from the quickmatch to the "lift charge" under the shell when its ready to be fired from the mortar. This is also how several shells are fired at once, or when you see a "setpiece" at a fireworks show where perhaps several hundred to several thousand lances are ignited nearly simultaneously to form a "picture in fire". You'll commonly see the American Flag, or the words "GOOD NIGHT" displayed as setpieces at many fireworks shows, and these all rely on quickmatch (or its close cousin "sticky match") to get lots of items lit in a hurry.
Quickmatch without the casing applied is known as "Black Match" which burns at perhaps a few inches per second. But when you apply the paper casing, or "pipe" you get a situation where the hot gases are compressed around the black powder as it burns, increasing the burn rate into hundreds of feet per second. In these videos you can actually see the quickmatch casing pressurize, and you can see the speed of the flame increase faster and faster until the casing bursts. The quickmatch has completed its job by the time the casing bursts, though.
What you're looking at in these videos is a 6" long piece of quickmatch clamped down with two pieces of black tape. The black tape is 4" apart - you have to anchor quickmatch down or it will propel itself around like an out-of-control water hose. There is an ematch folded into the left end of the quickmatch to start things off. The white dot you see early on in the video is our friend the LED, which is again wired up to show that were are applying current to the ematch - and then exactly when the ematch burns out.
12. Quickmatch - Waterproof Plastic Casing Type Video Here is another type of quickmatch that is wrapped in an additional layer of plastic for waterproofing. This type of quickmatch burns very fast, then the casing is literally ripped apart by the pressurized gasses inside.
13. Quickmatch - Domestic Type Video This type of match is supplied with a paper piping case, and is very, very reliable - It has a fairly large cotton-string core.. You can see that this has plenty of powder inside, a very fast burn rate, and will apply enough heat to whatever its connected to guarantee a good ignition to whatever device you're trying to light. The paper casing is strong enough to hold together until the very last part of the burn, where it begins to "give up" in sections.
NOTE: Yes, you CAN see the sparks and flame traveling rapidly through the paper casing / covering. That's because the camera is very sensitive to infra-red light (IR & "heat"), and paper is fairly transparent to IR. So we are actually able to "see into" the quickmatch piping as the fire shoots through from one end to the other. Neat-o!
14. Egg-Smash! Video So what does an egg have to do with pyrotechnics? Payment for the labor helping me to produce the shots above, that's what. I had to put this on for my daughters Irene (10) and Rebecca (14) who were willing assistants during this whole project - I had no shortage of volunteers for who got to be the "tosser" for this shot. This shot was captured at "only" 1,000 frames per second, but everyone loves the goo splatter everywhere.
Comments? Constructive Thoughts? Ideas for the next shot setups? email me at: firstname.lastname@example.org I can't promise a response to every email, but we try to get to them all.
On the next "shot list" we'll be turning the mortars sideways to the camera to get an idea of the lateral force of an explosion due to a shell malfunction. In addition, we're going for a shot of the shell in flight - for that we'll have the camera aimed at a section 12 to 15 feet above the mortar to get above the muzzle blast. Additionally, we'll be experimenting with stronger InfraRed filters to get a better shot of the flames without overloading the rest of the shot, as well as the use of fast welder's glass to snare a shot of that salute in mid-detonation.
Again, credits, references, and a heartfelt thanks go to:
Redlake HS-4 High Speed Video Camera, Redlake, San Diego, CA (www.redlake.com)