During my senior year at Ithaca College I did an independent study project involving high-speed photography. After 3 years of mathematics and physics courses, I wanted to do research that was more qualitative in nature. What I proposed was to use photography to investigate the evolution of a balloon popping. The basic setup involved a completely dark room, a camera with the shutter open (in bulb setting) and a special circuit board attached to a flash. The circuit was designed to detect a sharp noise and then detonate the flash. The flash itself was modified to generate the shortest burst of light possible. Such a setup accomplishes two important things (1) you have a means to electronically synchronize the event (e.g. a popping balloon) with the flash and (2) by using the duration of the flash to set the shutter speed, you can achieve far greater speeds than available from the camera’s mechanical shutter. The effective shutter speed from the flash is on the order of 1/10,000th second.
Once the setup is complete the fun begins! Depending on the proximity of the circuit to the balloon, you can capture different stages of the balloon popping. Put it close and you get the initial rip, move it back a few centimeters and now you get the final pieces of the balloon’s demise. This is shown in the series of 10 shots. Obviously each photograph is a different balloon being popped. What I tried to do is blow each balloon up to the same size and then, most importantly, puncture the balloon in the same location each time. For this series of photos you can see the needle popping the balloon from below. Another interesting study is observing how the evolution of a balloon popping depends on where you puncture it (bottom, side, top, etc…).
One of my favorite shots is shown below in which the balloon was popped from the side. The entire front half of the balloon has disappeared, allowing you to look at the interior of the far side of the balloon which is still holding it’s shape perfectly. Cool stuff.
The image I really wanted to capture was a water balloon popping – where the balloon itself has all but disappeared leaving a suspended mass of water in the exact shape of the balloon. Rather than soak the professor’s laboratory I was working in, I thought a better solution would be to sprinkle baby powder in a balloon. After popping the balloon, inhaling a good amount of powder and covering everything with white dust, I’m not so sure that the water balloon wouldn’t have been a better choice. Nevertheless, I was able to capture a fantastic shot. You can even make out the shock wave imprinted in the powder.
The best part of this whole project is how easy and affordable it is to do! My primary resource was HiViz which provides a easy to follow, comprehensive website dedicated to high-speed photography. I’d love to revisit this project using a digital camera. I’m going to get that popping water balloon yet…