[smidsy]

Hei Folks,
Doing a basic photography unit at uni and our next assignment is about speed & motion.
What I would like to do is set up the camera opposite the end of the barrel of my air rifle and catch the pellet in flight.

Obviously timing would be an issue and I may blow a fair bit of film to get some shots but I want to do something different.

The camera I have to use is a Minolta (I know this is a Pentax forum but I'm not allowed to use my Pentax auto gear for this class) X700 shooting Ilford HP5.
Any advice on this?
Cheers
Paul

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Last edited by smidsy; 05-05-2008 at 07:23 AM.

[TaoMaas]

Yeah, I think you can do it, but other folks will have to tell you exactly how. Your best bet would be to freeze the pellet by using a flash. And you'll need some sort of device to trigger the flash as soon as the pellet leaves the barrel of the gun.

[Lowell Goudge]

I can think of 2 ways to do this, and I would use the digital gear to figure it out, then take the film shot (i know that's cheating a little)

I would look for an Photo electric (beam) trigger for the flash and put the transmitter on one side of the barrel and the receiver on the other.

It should trigger when the pellet breaks the beam.

I would then use the exposure set to Bulb, with the apature set as needed for your flash, perhaps exposing correctly on the gun barrel

sequence would be lights off, open shutter, pull trigger, close shutter

[drabina]

set up the camera opposite the end of the barrel of my air rifle

Whatever you decide to do, make sure you do not shot yourself .... or the camera.

[siruami]

Take a look to:
Photo Gallery
Pictures 6 to 10.
He is Jonhy Chung, he is a great guy that may help you or guide you.

[simons-photography]

Whatever you decide to do, make sure you do not shot yourself .... or the camera.

yea i was rthinking that sure you can but you would at least smash a lens if you put it oposite the barel, why can't a digital be used ?

[séamuis]

why can't a digital be used

I'm assuming its a film photography course as most basic photography courses are.

[simons-photography]

well with film it could turn out to be a time consuming and exspensive endevour

[tbone-ike]

I don't have the knowledge to help with the timing and lighting, but with an air powered rifle, try using less air (an almost empty cartridge or fewer pumps, etc) and have the camera lense behind a clean peice of glass. Experiement before hand, of course, to make sure the glass is thick enough and wear safety glasses.

[little laker]

MythBusters did something similar, to see if a Ninja can swat a bullet out of mid air.
If I remember correctly they made up a simple device to trigger everything together.

If you can find the episode you may get some ideas.

Oh, and do yourself a favor, and have a sheet of plexiglas between the gun and camera

[christinelandon]

Paul, I suspect that nothing in your class requirements would keep you from working out the mechanics and timing of the setup while using your digital Pentax, then swapping in your Minolta once you've got everything synched and your exposure sussed out. Should save oodles of cash on experimenting with film.

[Rick]

Any advice on this?
Cheers
Paul

Some... hit the photography history books:




Harold Eugene Edgerton - Wikipedia, the free encyclopedia

This kind of photography is relatively common in ballistics labs to study bullet flight. How easily it is to replicate without lots of money and spendy equipment, I can't say. However, the amount of inexpensive technology available today would probably increase your odds. A pellet at around 400 fps is going to be a lot easier to deal with than a centerfire rifle bullet at around 3300 fps...

BTW, photographs of this kind are generally taken at about 100,000/sec and faster. With the equipment you will have on hand, the successful technique is probably going to be in the employment of your flash.

Let us know how you make out.

[bymy141]

Hei Folks,
Doing a basic photography unit at uni and our next assignment is about speed & motion.
What I would like to do is set up the camera opposite the end of the barrel of my air rifle and catch the pellet in flight.

Obviously timing would be an issue and I may blow a fair bit of film to get some shots but I want to do something different.

The camera I have to use is a Minolta (I know this is a Pentax forum but I'm not allowed to use my Pentax auto gear for this class) X700 shooting Ilford HP5.
Any advice on this?
Cheers
Paul

I think the timing of triggering the flash / camera related to triggering the gun is the real issue here.

A pellet moves around 1100 ft/s when exiting the barrel, this gives you 0.9 ms between pulling the trigger and executing the flash and opening the shutter. (If you want to catch the bullet in the first foot when exiting the barrel).
It's not shutter speed I'm worried about, as soon as the mechanism is triggered it is fast enough, it is the time required to start releasing the shutter.
You may need to create an electronic device to trigger the gun and the camera with variable delay timers (adjustable in 0.1 ms).

A more easy approach IMHO is taking a high speed film camera synchronized with a stroboscope.

Lots of success, and please show us the results.

- Bert

[Lowell Goudge]

I have to disagree with bert.

the shutter is not fast enough.

Essentually the 1/4000 second shutter speed is not the time the shutter opens or the time it takes to travel top to bottom

That time is more closely 1/180th of a second, i.e. the maximum sync speed.

At speeds beyond 1/180th the shutter is never fully open, only a slit moving vertically and the width of the slit is simply set to give 1/4000 of a second open time, based upon the speed of the shutter blades.

Also, I disagree with the statement that the speed is 1100 feet per second. This is not possible, as it would then be supersonic, (note speed of sound is 1000 feet per second) and the pellet gun would be a lethal weapon, plus it would make a hell of a lot more noise than it does.

Having said that however, it will still be difficult to get timed correctly, even with a photo sensor operated flash.

You would need to consider the field of view of the camera, and the time to traverse the frame, with your field of view and camera to gun distance.

It might be better to do a couple of things differently, first, fire the flash based upon the trigger, and second use the flash in a "strobe mode" perhaps the high speed sync mode, where there are multiple flashes as one might just catch the pellet

[alohadave]

I think the timing of triggering the flash / camera related to triggering the gun is the real issue here.

A pellet moves around 1100 ft/s when exiting the barrel, this gives you 0.9 ms between pulling the trigger and executing the flash and opening the shutter. (If you want to catch the bullet in the first foot when exiting the barrel).
It's not shutter speed I'm worried about, as soon as the mechanism is triggered it is fast enough, it is the time required to start releasing the shutter.
You may need to create an electronic device to trigger the gun and the camera with variable delay timers (adjustable in 0.1 ms).

A more easy approach IMHO is taking a high speed film camera synchronized with a stroboscope.

Lots of success, and please show us the results.

- Bert

Or you can shoot a long exposure shot and use a sensor to trigger a strobe, like this:



He used instructions from High-Speed Visual Imaging to make the trigger and strobe firing assembly.