Your Flash is too SLOW

WhiteLight

Senior Member
Capture bullets in flight with the first safe, affordable high-speed camera flash.

Your flash is too slow

High speed photography relies on a fast flash. Just like shutter speed with action photography, it's the duration of the flash that is important when capturing bullets and explosions. A typical speedlight has a duration of around 1/20,000 second (50 microseconds) on its fastest setting. This may sound fast, but a bullet will travel over 5cm or two inches in that time and will be so blurred it's almost invisible. Studio flashes are even slower. For pin-sharp shots you need a much faster flash, and the Vela One is 100 times faster. With a flash speed starting at 1/2,000,000 second, or 500 nanoseconds, the Vela One will stop a supersonic, high velocity rifle bullet in its tracks.

[video]https://d2pq0u4uni88oo.cloudfront.net/projects/1330259/video-467808-h264_high.mp4[/video]

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It's definitely seedless now.

High speed photography today

We've all seen the beautiful high speed shots of bullets passing through playing cards and apples. If you want to take these sort of photos today, you will either need a high speed camera costing tens of thousands of dollars, or a dangerous and expensive air gap flash. These use a high voltage spark to generate the short, bright flash needed. As they run at over 25,000 volts and need regular and dangerous electrode replacement, it's not surprising you can't buy them commercially. If you want one you either need to buy a vintage one for thousands of dollars, or you must build one yourself. Many super talented people have done this, but it's not an option for most of us. We wanted to solve this.

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Passata di pomodoro


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MORE & Source - https://www.kickstarter.com/projects/vela/vela-one-the-worlds-first-high-speed-led-flash
 

FastGlass

Senior Member
I guess my question is at what power level. The lower the flash output the faster the flash. So at 1/2,000,000 of a sec duration, what is the power at this point?
 

Horoscope Fish

Senior Member
Not that I'm not impressed but someone needs to point out the projectile in those photos is NOT a bullet, it's a BB: a projectile fired from an air-rifle (or air-pistol) and yes, there really is a significant difference between the two. One of those key differences would be the velocity of the projectiles they fire, which seems to be of particular relevance here. While that BB is probably moving at, say, 800 feet per second (and I'm being generous with that number) bullets fired from firearms routinely travel at speeds of 3,000 feet per second and many are much faster than that. I can't help but notice they don't mention specific velocity but that's okay. All that being said, I *do* take exception to them saying, or implying, their product will freeze a bullets travel, because it won't.

Again, I'm not trying to "knock" the product, I'm just pointing out there is some clever marketing being employed here.

....
 

Bob Blaylock

Senior Member
Not that I'm not impressed but someone needs to point out the projectile in those photos is NOT a bullet, it's a BB: a projectile fired from an air-rifle (or air-pistol) and yes, there really is a significant difference between the two. One of those key differences would be the velocity of the projectiles they fire, which seems to be of particular relevance here. While that BB is probably moving at, say, 800 feet per second (and I'm being generous with that number) bullets fired from firearms routinely travel at speeds of 3,000 feet per second and many are much faster than that. I can't help but notice they don't mention specific velocity but that's okay. All that being said, I *do* take exception to them saying, or implying, their product will freeze a bullets travel, because it won't.

Again, I'm not trying to "knock" the product, I'm just pointing out there is some [not very] clever marketing lying being employed here.

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Fixed it for you. Or would have if this forum supported the “strikeout” tag.

It's clear that they've made a very poor attempt at deception here. Their product may or may not perform as they claim, but their use of images of a BB fired from a BB gun to support their claims about how normal speedlights would fail, and their product would succeed, at capturing high-speed bullets, is outright fraudulent. I have to think they've engaged in some deception, even, to get the image showing a speedlight failing to stop a BB. I have little doubt that a BB would be moving slowly enough for a normal speedlight to capture it just fine. In fact, I have a distant memory of a friend of mine taking pictures of .22 bullets in flight, and I am fairly sure that he used a normal speedlight for that.


I think your estimate of how fast that BB could be moving is on the generous side—realistic, perhaps, for a high-end air rifle, but those don't shoot BBs; they shoot special lead pellets that are very distinctly different from BBs. In fact, you'd damage an air rifle if you used BBs in it.

Pictured here, some .177 caliber air rifle pellets.

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WayneF

Senior Member
I would not call that deception. Their video says flash duration of up to two millionth of a second (I don't know how bright that could be?) Their claim is that is faster than a speed light (a couple of orders of magnitude perhaps, my words, not theirs). A speedlight possibly could be made faster, but not sure how it would sell? (we seem to want more power and light from it).

What they show is certainly not Daisy BBs. 22 caliber rifles do not go 3000 feet/second either, maybe 1000 to 1200 f/s. And here is a Wikipedia reference (air gun) to air rifle round balls approaching 1000 feet/second in the 17th century:

"In the 17th century, air guns, in calibers .30–.51, were used to hunt big game deer and wild boar. These air rifles were charged using a pump to fill an air reservoir and gave velocities from 650 to 1,000 feet per second (200–300 m/s). They were also used in warfare; the most recognized example being the Girandoni Military Repeating Air Rifle."

We probaby do compression better today? :) I don't see the problem?

I have absolutely no interest in this, other than addressed here, but here is more info:
https://www.kickstarter.com/projects/vela/vela-one-the-worlds-first-high-speed-led-flash

It says one million lumens when run at 20 times rated power (for a short duration).

If 1/2,000,000 second duration, I think that would be 1/2 lumen.


But (about bullets and GN) see the FAQ at page bottom at

Vela One - the fastest flash in the world by Vela Labs — Kickstarter
 
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Horoscope Fish

Senior Member
Fixed it for you. Or would have if this forum supported the “strikeout” tag.

It's clear that they've made a very poor attempt at deception here. Their product may or may not perform as they claim, but their use of images of a BB fired from a BB gun to support their claims about how normal speedlights would fail, and their product would succeed, at capturing high-speed bullets, is outright fraudulent. I have to think they've engaged in some deception, even, to get the image showing a speedlight failing to stop a BB. I have little doubt that a BB would be moving slowly enough for a normal speedlight to capture it just fine. In fact, I have a distant memory of a friend of mine taking pictures of .22 bullets in flight, and I am fairly sure that he used a normal speedlight for that.


I think your estimate of how fast that BB could be moving is on the generous side—realistic, perhaps, for a high-end air rifle, but those don't shoot BBs; they shoto special lead pellets that are very distinctly different from BBs. In fact, you'd damage an air rifle if you used BBs in it.

Pictured here, some .177 caliber air rifle pellets.
I'm a long time rifle/pistol shooter from the Midwest and I'm very familiar with BB-guns, pellet rifles and so forth. In fact I cut my teeth stalking prairie dogs with Crossman 870 (and actually managing to take a few out) before my dad gave me my first Remington .22LR bolt-action for the very "serious business" of eliminating a particularly pernicious badger at age 12. I used the particularly generous "800 feet per second" knowing it was generous but figured someone would come along and bring up pellet rifles which are indeed much more powerful. I would know, I've shot both rifles and pistols competitively most of my life. For the very brief period I shot air my Beeman would put .177's out the muzzle at roughly 1100 FPS. I was using 800 FPS as a broad brush is all, not wanting to bog down my argument with too much detail; as I'm probably doing now.

All that being said, I was soft-pedaling my opinion in my previous post but, since we're taking the gloves off, yes... I agree with your assessment completely: The claims they make are blatantly misleading, gross overstatements and not by any mistake whatsoever.

...
 

J-see

Senior Member
If we'd be nerdy we could calculate the speed that bullet would have traveled when using a DSLR. At 1/8000s shutter there's only so far something can go. What's the size of an average tomato these days? ;)
 

J-see

Senior Member
I can't resist these things. A BB bullet travels below the speed of sound; that's 340m/s or 4.25cm at 1/8000th of a second. To freeze that you'd need to be at such a distance the 4.25cm is a to be neglected amount of pixels else you have motion blur.
 

Eyelight

Senior Member
The developer is just lacking in basic gun knowledge. He's selling flash gizmos and so the focus is on the flash gizmo.

Video clearly labels it as a BB at 300 fps.

At 1/2,000,000 it would effectively freeze an object traveling at 3,000 FPS. Actually, the object would move .018 inches, so might be a smidgeon of blur.
 

J-see

Senior Member
300fps. I had to convert that to know if its fast. That's not even 100m/s.

I guess he never has been in the army and handled a rifle.

I was mostly curious if I could take such a shot with the DSLR.
 
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fotojack

Senior Member
Up here, you can't buy a pellet gun that is over 495 fps. After that, it's considered a firearm. I have two pellet guns (that shoot the pointy lead pellets) with a muzzle velocity of 490 fps.

In the above photos, that certainly looked like a BB to me, and not a bullet.
Anyway, I digress. Yes...I agree that they're most certainly flogging the flash unit gizmo. I wouldn't take them seriously at all.
 

FastGlass

Senior Member
Not that I'm not impressed but someone needs to point out the projectile in those photos is NOT a bullet, it's a BB: a projectile fired from an air-rifle (or air-pistol) and yes, there really is a significant difference between the two. One of those key differences would be the velocity of the projectiles they fire, which seems to be of particular relevance here. While that BB is probably moving at, say, 800 feet per second (and I'm being generous with that number) bullets fired from firearms routinely travel at speeds of 3,000 feet per second and many are much faster than that. I can't help but notice they don't mention specific velocity but that's okay. All that being said, I *do* take exception to them saying, or implying, their product will freeze a bullets travel, because it won't.

Again, I'm not trying to "knock" the product, I'm just pointing out there is some clever marketing being employed here.

....
A bb? I don't know but looking at the size of the tomato, it looks a little big for a bb.
 

Horoscope Fish

Senior Member
A bb? I don't know but looking at the size of the tomato, it looks a little big for a bb.
I thought so too, at first. Then I realized in the first shot the BB is passing through a grape and in the second, that's what I know as a Cherry Tomato; one of those really little ones you'd put on a salad, whole.

....
 

Bob Blaylock

Senior Member
I'm wondering about another line of claims that he makes…

If you want to take these sort of photos today, you will either need a high speed camera costing tens of thousands of dollars, or a dangerous and expensive air gap flash. These use a high voltage spark to generate the short, bright flash needed. As they run at over 25,000 volts and need regular and dangerous electrode replacement, it's not surprising you can't buy them commercially.

He repeats this claim a number of times, including this graphic, with the caption “Top feature: it won't kill you!”

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Anyone know about, or have any experience with, these air gap flashes he mentions? They aren't really that dangerous, are they? I know that normal electronic flashes typically run at about five hundred volts, which would be plenty dangerous if there was enough current to back it, and an easy enough way to come in contact with it. I also know that it's possible to be exposed to static electricity in the millions of volts, with no ill effects. I'm not familiar with these kind of flashes, but I have a feeling that he is greatly exaggerating their danger, if not outright lying about it.
 

WayneF

Senior Member
I'm not familiar with these kind of flashes, but I have a feeling that he is greatly exaggerating their danger, if not outright lying about it.

There probably are some marketing words, but he is speaking of 1/2,000,000 seconds duration, and I think 500 volts simply will not do it. I don't know what a price would be, but it will cost more and be more dangerous than speedlights.

Nikon speedlights run about 320 volts on the capacitor. They contain such a power converter that runs on the AA batteries (the recharge whine we hear). The external battery packs are similar (maybe larger) power converters outputting this 320 volts directly to the capacitor, for faster recycle. Either way, the capacitor voltage is what it is.

Monolights may be 500 volts (AB is), and typically turn the voltage down to decrease their power level. Easy, but this lower voltage typically slows them down to a longer about 2x duration (less power to push them)... and makes the flash be more red color.

Speedlights always trigger at the one full voltage, and then their duration is cut off, quenched to stop it, to provide a shorter flash at less power rating. These become more blue at low power, by cutting off the trailing low power decay tail. At 1/128 power,the SB-910 spec is 1/38,500 second duration. That is not in the same class as 1/2,000,000 second.

Speaking of flash tubes instead of LEDs, my notion is that to have any usable amount of light output at 1/2,000,000 second duration, we are going to have to start at a much higher power level. I think we are speaking of thousands of volts (for flash tubes).

You can read about Harold Edgerton, who basically invented the flash tube in the late 1920s. He began with spark gaps, and then xenon flash tubes, specifically meaning high speed flash then, and he did the first milk drop splashes, etc (then he and his work were later on very important in the WWII effort). He had no thyristors yet, but he was using 5000 volts on the capacitors. I would call that dangerous.

One can seriously be hurt in a speedlight if they open the case and prowl around. A capacitor is not limited in the current it delivers. Flash tubes operate around 2400 amps/per sq cm area (term is current density), which is what ionizes the xenon gas. The flash dumps a capacitor energy charge of maybe 75 to 2400 watt seconds nearly instantaneously.
 
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