(click here for a larger view)
In this example I captured a falling drop in various stages of its fall.
For this picture I used the following components:
- Camera and flash.
- Universal Photo Timer.
- Optical sensor (UPT_OS1).
- A laser pointer.
- Dripping faucet.
The Universal Photo Timer was used to activate the camera (no need for a dark room). To trigger the unit I used a standard off the shelf laser pointer as the light source and a light sensor to detect the presence or absence of the laser beam.
I placed the laser and the sensor several feet away. The laser was pointed at the tip of the faucet and at the sensor. As the drop was forming, the laser beam was deflected activating the sensor.
Since the shutter lag of a camera is at best 100ms, it is impossible to take the picture of the falling drop that has triggered the sensor. Since the drops are forming at the constant rate (roughly 2 seconds), I decided to trigger on one drop and take a picture of the following drop.
The unit can automatically increase the delay for repeated pictures allowing me to capture the sequence of drops in various stages of fall without the need to manually adjust the delay. The picture was edited in PS to combine the frames.
As an option, you can wire the laser to be turned off during exposure so that you would not see the red light at the top of the picture. The unit contains an output in the sensor connector that switches the power off to the sensor itself.