Amazing photo made at the range today.
- Thread starter Lightsped
- Start date
- Status
To expand a bit on what itgoesboom and others have mentioned about flash photography, many modern flash units, including built-in units, will adjust the flash output by using a light detector in a feedback loop. They adjust the output by varying the length of flash anywhere from 1/1000th sec. (slowest & most flash) to as fast as 1/50,000th sec. Since in the photo in question the flash would have been in the shorter range since it is overpowered by the white shirt in the foreground. The flash would have fired for a shorter time than if the shooter had not been in the picture. I would estimate the flash could be anywhere from 1/2,000th to 1/5,000 of a second - fast enough to stop a plodding .45 in its tracks especially at the angle of the line of flight. That is assuming the unit is a variable flash unit, which wouldn't be at all unusual.
Nathaniel Firethorn
Member
Time to do some rough math. Everything is rounded to two digits.
The object is about halfway downrange. It looks like the target is at about 50 feet, so let's assume that the object is 25 feet away from the shooter. Assuming it's the bullet and that it's moving at 900 ft/sec, that would mean that the picture was taken about 28 milliseconds after ignition.
The shooter's hand has recoiled about 6 inches in that time. Compute the acceleration on his hand needed to make this happen. Since d = 1/2 a t^2, a = 2d/(t^2) = 2 * 0.5 ft / ((0.028 sec) ^ 2) = 1300 ft/sec^2. About 40 gees.
Now velocity of his hand: v = at = 1300 ft/sec^2 * 0.028 sec = 36 ft/sec or 24 mph. Relatively gentle, though I'd want it to slow down in a hurry! (This is simplistic because the shooter is going to be decelerating his hand.)
Energy now: Let's say that the shooter's hand plus gun weigh about five pounds. Its mass is then 5 pounds / g = 5 pounds / 32 ft/sec^2 = 0.16 slugs.
On to energy: e = 1/2 m v^2 = 1/2 * (36 ft/sec)^2 * 0.16 slugs = 100 foot-pounds. Well within what a .45 can produce, if I remember correctly.
So the physics, at this point, doesn't rule out the possibility that it's the bullet.
Feel free to poke all the holes you want; I'm rusty at this.
- pdmoderator
The object is about halfway downrange. It looks like the target is at about 50 feet, so let's assume that the object is 25 feet away from the shooter. Assuming it's the bullet and that it's moving at 900 ft/sec, that would mean that the picture was taken about 28 milliseconds after ignition.
The shooter's hand has recoiled about 6 inches in that time. Compute the acceleration on his hand needed to make this happen. Since d = 1/2 a t^2, a = 2d/(t^2) = 2 * 0.5 ft / ((0.028 sec) ^ 2) = 1300 ft/sec^2. About 40 gees.
Now velocity of his hand: v = at = 1300 ft/sec^2 * 0.028 sec = 36 ft/sec or 24 mph. Relatively gentle, though I'd want it to slow down in a hurry! (This is simplistic because the shooter is going to be decelerating his hand.)
Energy now: Let's say that the shooter's hand plus gun weigh about five pounds. Its mass is then 5 pounds / g = 5 pounds / 32 ft/sec^2 = 0.16 slugs.
On to energy: e = 1/2 m v^2 = 1/2 * (36 ft/sec)^2 * 0.16 slugs = 100 foot-pounds. Well within what a .45 can produce, if I remember correctly.
So the physics, at this point, doesn't rule out the possibility that it's the bullet.
Feel free to poke all the holes you want; I'm rusty at this.
- pdmoderator
Double Naught Spy
Sus Venator
Pendragon, how did you determine the round to be a .45 as Lightsped has not provided us with that information?
How do you figure that .45 acp is one of the lowest flashing calibers? It isn't the caliber that determines the flash, but things like the amount, and speed of the powder, barrel length, etc.
Here is a picture of one of those low flashing .45 types of Ammo, Aguila. The image was taken at dusk with an Olympus 2.1 megapixel digital camera and flash. The image was captured using a timer while the shooter what losing whole magazines of ammo.
How do you figure that .45 acp is one of the lowest flashing calibers? It isn't the caliber that determines the flash, but things like the amount, and speed of the powder, barrel length, etc.
Here is a picture of one of those low flashing .45 types of Ammo, Aguila. The image was taken at dusk with an Olympus 2.1 megapixel digital camera and flash. The image was captured using a timer while the shooter what losing whole magazines of ammo.
Attachments
He said he was using a Glock 30, so he did, in essence, tell us what caliber it was. But I sure wish he would come back and give us some camera/ammo/distance info as well.
BTW, did the shooter ever find his magazines?
BTW, did the shooter ever find his magazines?
Nando Aqui
Member
Actually, Double Naught Spy just beat me to it. What caught my attention was the 'beam' that looks like it's about to drop off. I thought about the white dot being the bullet, but dismissed that notion completely until I read the other comments.
I have done quite a bit of high speed photography to catch manufacturing equipment and other machinery 'in the act', such as when a centrifugal switch of an electric motor actually operates, and I can say that unless the shutter speed if extremely fast, the bullet would look like a blurr at best.
If the bullet is traveling at 1000 FPS (approximately, to make things easier), it would take it 1/1000 sec to travel one foot. If the shutter speed were 1/1000 (pretty fast) the bullet would appear as a streak about one foot long, which is how far it would have traveled while the shutter was open.
To appear as a dot, say about 1/2" long, the shutter would have to stay open for the length of time the bullet would take to travel the 1/2". Since there are 24 half-inches in a foot, the shutter speed would have to be 1/24000. Make sense?
My 2¢
Alex
I have done quite a bit of high speed photography to catch manufacturing equipment and other machinery 'in the act', such as when a centrifugal switch of an electric motor actually operates, and I can say that unless the shutter speed if extremely fast, the bullet would look like a blurr at best.
If the bullet is traveling at 1000 FPS (approximately, to make things easier), it would take it 1/1000 sec to travel one foot. If the shutter speed were 1/1000 (pretty fast) the bullet would appear as a streak about one foot long, which is how far it would have traveled while the shutter was open.
To appear as a dot, say about 1/2" long, the shutter would have to stay open for the length of time the bullet would take to travel the 1/2". Since there are 24 half-inches in a foot, the shutter speed would have to be 1/24000. Make sense?
My 2¢
Alex
gun-fucious
Member
the first post said it was a Glock 30 ergo .45
Anyone one else want to calculcate how far a .45 slug travels at 1000 fps
for the camera flash's 1/1000ths of a second duration?
Occam's razor says its a bullet
Anyone one else want to calculcate how far a .45 slug travels at 1000 fps
for the camera flash's 1/1000ths of a second duration?
Occam's razor says its a bullet
Double Naught Spy
Sus Venator
Mal H and Pendragon, I stand completely corrected on the .45 issue. Cany you tell I don't do Glocks? Sorry.
Alex, in general, shutter speed means zip in flash photography as long as it overlaps the flash and the flash is the main source of light (e.g., not fill-in flash).
gun-fucious
Member
we orbit similar spheres here
as the bullet is more or less moving directly away from the camera
the bullet would not render as a streak
but as a dot
as the bullet is more or less moving directly away from the camera
the bullet would not render as a streak
but as a dot
Double Naught Spy
Sus Venator
Just curious, how come the flash managed to stop the bullet that was traveling at 800+ fps and yet the shooter's right hand shows a streak effect on the left side when the hand wasn't traveling at several hundred feet per second? I find it odd that the supposed bullet is so perfectly preserved by that the hand was not.
Uh, oh! You're starting to repeat yourself.
I'm not sure what you mean by the streak on the hand. His right hand looks well focused and not blurred in the least. I assume all parts of the hand(s) and gun are moving at roughly the same speed yet they look like they are still due to the flash duration.
I'm not sure what you mean by the streak on the hand. His right hand looks well focused and not blurred in the least. I assume all parts of the hand(s) and gun are moving at roughly the same speed yet they look like they are still due to the flash duration.
Nando Aqui
Member
Mal H & gun-fucious
(1) Correct - this would be under regular lighting condition; not flash.
(2) Yes, what I said applies only to the camera at right angle to the bullet path, which is not the case here, obviously.
But even if the camera were about two feet from the bullet path, that 'dot' would start out as a streak, and become more of a dot as it traveled down range. The closer the bullet is to the target when the image is taken, the shorter the streak, but also the smaller the image.
The bullet image would be all 'dot' and no streak if the camera were mounted right on the pistol. Then, if the target were 25 yards away, the camera would theoretically have (25yd x 3ft/yd)/1000fps = .075 seconds to capture the bullet as a speeding 'dot'.
Oh well.... enough of this for now...
Nice picture anyway -
Alex
(1) Correct - this would be under regular lighting condition; not flash.
(2) Yes, what I said applies only to the camera at right angle to the bullet path, which is not the case here, obviously.
But even if the camera were about two feet from the bullet path, that 'dot' would start out as a streak, and become more of a dot as it traveled down range. The closer the bullet is to the target when the image is taken, the shorter the streak, but also the smaller the image.
The bullet image would be all 'dot' and no streak if the camera were mounted right on the pistol. Then, if the target were 25 yards away, the camera would theoretically have (25yd x 3ft/yd)/1000fps = .075 seconds to capture the bullet as a speeding 'dot'.
Oh well.... enough of this for now...
Nice picture anyway -
Alex
Double Naught Spy
Sus Venator
Pappy John
Member
Okay, so lighting conditions on most indoor ranges consist of the shooting station being lit and the target being lit.....all else unlit. So the hands are not flash dependent for exposure since the shooter's station is lit by house lighting, while the bullet, being half way to target is only lit during flash duration. Sooooo....... the hands could show motion while the bullet is frozen by the flash.
Whew.
To me, thats a bullet. I've seen them in flight often enough on the range that I think you might have to be lucky to catch one on film like this, but its not all that suprising to see it caught by a flash. Especially them big ol' slow .45's
Whew.
To me, thats a bullet. I've seen them in flight often enough on the range that I think you might have to be lucky to catch one on film like this, but its not all that suprising to see it caught by a flash. Especially them big ol' slow .45's
If it's a standard 230g load, the MV out of a short G30 barrel would be well under 800 fps. So call the velocity of the bullet in flight at the time of the picture 750 fps, rather than 1000 fps. Sounds like it's splitting hairs, I know, but that 25% reduction in velocity is important.
gun-fucious
Member
digital camera tend to halo high contrast objects and introduce noise
We have noticed that whenever you shoot fields of long grass, there is noise where the stalks cross
film don't do that
We have noticed that whenever you shoot fields of long grass, there is noise where the stalks cross
film don't do that
mephisto
Member
I think it is the bullet. As for the flash? Look at the pic and you can see some pixilation around the end of the barrel. It looks, to me, that you are getting the last bit of flash. Look at the contrast with the wall. What the hell am I trying to say? I don’t know.


Keith
Member
Duh!
I think I just figured it out. It isn't camera flash lighting the base of the bullet, it's the spotlight focused on the target!
The slug has just passed beneath a beam. On the back side of that beam is a spotlight focused on the target - or actually not quite pointed at the target, if you compare his target with the one in the next lane.
Anyway, since you can easily see a .45 in flight, there's no reason a camera can't take a picture of it. All of you guys are probably correct about the duration of flash, etc, but that isn't what is lighting up the slug.
Pretty neat!
Keith
I think I just figured it out. It isn't camera flash lighting the base of the bullet, it's the spotlight focused on the target!
The slug has just passed beneath a beam. On the back side of that beam is a spotlight focused on the target - or actually not quite pointed at the target, if you compare his target with the one in the next lane.
Anyway, since you can easily see a .45 in flight, there's no reason a camera can't take a picture of it. All of you guys are probably correct about the duration of flash, etc, but that isn't what is lighting up the slug.
Pretty neat!
Keith
Lightsped
Member
No double tapping during this range trip....
Yes, the range is Eds guns near Town Center Mall.
Yes, the range is Eds guns near Town Center Mall.
- Status
Similar threads
- Locked
- Locked
