The pictures were taken in the garage. The water balloon is on the cutting board, with some guy apparently me many years ago holding a knife ready to swing down and slice the balloon. On the right side is an old fashion movie projector, the light shining through a cardboard hole, creating a beam of light going across to the light sensor on the other side. Some electronics I devised connects the light sensor to the camera flash seen in the lower right of the photograph.
When the knife is swung down slicing the balloon, the light beam is broken and the camera flash is triggered. The brief flash of light from the camera flash captures the moment.
To take the picture, the picture is taken at night with the garage door closed making it pitch dark. My brother pushes the button on the chord attached to the camera which opens the camera shutter. He yells, "Shutter open!" I swing the knife down, the camera flash activates capturing the moment and exposing the film. My brother releases the camera's shutter button closing the shutter and says, "Shutter's closed." We grope for the light switch and look at all the water on the table and garage floor.
The water rocket ascends about 40 feet in 1 second. This photo is taken approximately 40 milliseconds after liftoff.
Actually it was pitch dark in the garage when these water rocket pictures were taken. For this photograph I'm just pretending to watch the rocket by looking at where I think the rocket will be when the picture is taken.
It's also difficult to position the rocket so it passes through the infra-red light beam above it. Since we can't see the infra-red beam we first had to determine where it was by moving our hand or an object around the general area and watch the volt meter connected to the receiver at the other end of the beam. We watched until the volt meter made a significant swing, indicating to us that we had found the beam by blocking its path to the sensor. I had to position the rocket so it was nicely framed in the camera and also directly underneath the invisible beam. After the lights were shut off I had to be careful not to tilt the rocket to one side when I launched it, which it had a tendency of doing.
The same concept is used as in the water balloon pictures, except I improved the setup this time. Instead of using an old fashioned movie projector as the source for a light beam, I used an infra-red LED focused through some binoculars creating an invisible beam of infra-red light passing across the table to the sensor on the other side. This way the beam of light wouldn't show up in the picture.
It was rather difficult to focus the beam of infra-red light on the sensor at the other side of the table because we couldn't see it. We had to rely on a meter measuring the strength of the received beam and move the binoculars around until we arrived at the maximum level.
The electronics I devised for this setup were fancier as it allowed for an adjustable delay between the time the beam is broken and the camera flash is triggered.
There were some extra difficulties when taking these shots. First of all since we couldn't see the infra-red beam of light going across the table I wasn't sure exactly where to position the rocket so it would pass through the infra-read beam when launched. Finding the beam took some time, again looking at the meter measuring the strength of the received beam to tell us when the beam was broken.
Another problem was launching the rocket itself. The rocket typically travels upwards about 40 feet in a second with great force. Our garage ceiling is only about 12 feet high, so a rocket catcher device had to be built and attached to the ceiling to catch the rocket after it was launched.
This is the photo which inspired my water balloon and water rocket photos. This picture was taken at the famous Brooks Institute School of Photography circa 1982. It’s a picture of a lady’s hand holding an egg with a bullet going through it. You can just make out the bullet emerging on the right side as the egg is beginning to explode. The picture was taken by faculty members Mike Verbois and Manny Maes for the Tokina Optical Corporation, the largest photographic lens manufacturer in the world. The advertising campaign was "Tokina sees what the eye can’t". Full size posters of the picture were made. The lady with the slender fingers holding the egg is the photographer’s wife.
The photographers explain how they made the photo:
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When the projectile erupted from the barrel it split a light beam which in turn activated a micro processor set to fire electronic strobes positioned above the egg. A delay of about 921 milliseconds had been programmed in the delay system so it activated the Strobotaus at the moment the bullet was shattering the egg some 25 inches from the barrel. The brief burst of light, of three microseconds (three millionths of a second) illuminated the bullet, the hand, and the egg together. The Tokina 35-105mm lens was set on a Canon AE-1 camera with the shutter on time exposure and the aperture on f4.5. Ektachrome 200 film was used. One of the many technical problems encountered was the actual velocity of a .22 Long Rifle projectile. Nominally this is 1100 ft/sec but even the slightest variation was critical so one of photography's oldest techniques was used: do a lot of testing. Tension built up during the testing and when it came to the final shoot little had been done to ease that tension. Dennis Globus takes up the story: "With everything checked, re-checked, and re- re-checked a thousand times. .. we were finally ready for the first shot. Betty casually took her place underneath a protective shield that covered her entirely except for a small opening through which she stuck her hand. Manny and Mike devised a “brace” that would hold her hand in place, preventing her from moving into the bullet’s path. "Mike took his place behind the camera. Manny clutched the remote firing device in his fingers. And I turned out the lights. "Mike dutifully announced, ‘Shutter's open’! And, with some effort, Manny said, ‘Ready’! And I bit my lower lip. "We heard CRAAACK, saw a flash of light, and it was all over. Mike excitedly yelled, ‘The shutter's closed’! And I flipped on the room lights. Our eyes immediately went to what we hoped would still be Betty's hand. And there it was, totally covered with egg yolk. In fact, as we looked around the room at each other in amazement, we realized we were all covered with egg yolk. It was everywhere! I'm not sure who it was, but one of us starred to giggle. Soon, we were all looking at each other and pointing, laughing hysterically. Talk about having egg on your face . . . wow!" (Not mentioned in this article, the lady is not actually holding the egg. The egg is fixed on a stand. A special brace was made for the lady's hand to hold it in place. Take a closer look at the picture. Only one finger is touching the egg, the rest are curled safely out of the way. And the one finger that is touching the egg is positioned below the path of the bullet.) |
Another photo they created:
Dual-Input Dual-Output Digitally Controlled Delay Timer I Created for taking High Speed PhotographsBack to David Deley’s Home Page