High Speed Photography - Part I

 

 

The art of high speed photography must be one of the most interesting ways that photography can represent things we see, and don't see, everyday. Photos of bullets piercing armour, hammers smashing watermelons and pins pricking balloons are all possible due to the technological advances in cameras.

There is, however, a cheap and dirty way of producing high quality high speed photographs at home, and this is what I want to show you here! This method uses no special cameras and likely costs less than a thriller novel.

Any camera which can be set on 'exposure priority' mode will work. Basically, in this mode, the user can manually set how long the camera shutter opens. Generally a few seconds will do the trick. To put this in contrast, a picture shot outdoors in broad daylight will generally have an exposure time something like 1/500th of a second. The key in our setup is darkness - the camera and scene is setup in darkness, and the only light comes from a sound activated flash unit.

This is the crude setup which I used. The red device is a custom sound activated flash unit which I put together using an old camera flash unit (careful with these...), a microphone, and an amp circuit.

The red cross is where the camera is placed to capture the action and the blue circle is where the 'action' takes place.

Here is one of the earliest photos during the testing phase. This is just some random stuff being dropped onto the tiles.

Notice how nothing has hit the surface. You're probably thinking, then how on earth did the sound trigger get activated?

Well in fact, the COIN has hit the floor, except there is a tiny delay between sound activation and the flash caused by a relay, so the coin you see is actually bouncing back UP.

 

More junk being dropped. The microphone is visible on the left.

That over-exposed section on the backboard is caused by the uneven spread of the flash lamp - I must make a diffuser of some kind.

Coins being dropped onto the tiles.

The flash is activated the moment the small 5 cent coin at the bottom hits the floor whilst the other coins are still falling.

I never thought this would be caught in action...

An attempted snapping of a CD, but instead it bent and flew out of my hand very quickly.

Of particular interest is the 'flexing' motion of the CD caught in still-motion! This setup is working well!

A more successful CD snapping. Bits going everywhere... The flash was triggered twice in this exposure, because some of the CD shards hit the microphone after the first flash. This explains why the scene appears "ghostly".
Similar to the above. This is a better exposure, however. Different CD, obviously...

The lightbulb smashing photo is a classic, and I couldn't resist doing one. This is a very weird one, because the bottom half of the bulb is already gone, but the glass hasn't risen up in the air yet.

The perfect bulb smash photo was never taken, because the flash trigger was relatively too fast, and the glass never had enough time to break up properly.

The poor giraffe starting to fall after being hit at high speed by a flying elephant.
The poor giraffe once again, this time doing a handstand.

A wire spool and an elephant were thrown together.

I love this one, and it is a classic stroboscopic example. The flash in this exposure was triggered 3 times, and each time the camera recorded the location of both objects.

As you can see, the elephant was brutally thrown off the wire spool and hit the corner.

The elephant being dunked in water at very high speed.

It is difficult to obtain correct exposure of these photos, given the lighting is intense and short-lived. It appears the only real solution is software correction, but perhaps a brigher flash unit along with a diffuser would help.

My favourite high speed photo - water being splashed onto a glass dish.
This one is kinda spooky. Here the stream of water which first hit the dish triggered the flash while the rest was still falling.
Here is a great demonstration of flash delay. The screwdriver has already hit the surface, but has bounced back up by the time the flash is triggered. This is due to the time it takes for the relay to switch on and trigger the xenon flash lamp to arc.

This is a zoomed-in image of the same ceramic statue that was shot by the Coilgun a few weeks prior. I decided it wasn't worth anything anymore so I dropped it. At the time I felt like breaking something anyway, which is what this whole section is about.

Notice the fine grains of porcelain being chipped off while a large verticle crack forms in the body.

There is another type of high speed photography which requires even less setup and equipment - check out part II.

 

 

 

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