Simple drip apparatus (dripper) for drop photography
When photographing drops, the first problem to overcome is to build an apparatus which emits drops with a stable interval. This article describes how to build a simple yet elegant home-brew drip apparatus (also called a dripper, emitter or just drop generator). The construction is rather trivial. The setup is show in the picture below. The materials you need are:
- thin flexible tube (e.g. heat shrink tube)
- clothes pin
- something to clip the clothes pin on
The drop interval can be adjusted by simply changing the level of the tube outlet relative to the water level in the bottle. Of course the outlet must keep below the water level. The bigger the level difference, the shorter the drop interval. Too large level differences will result in a continuous water stream. If you are interested in physics you might want to know that the dependency between the water level in a tank and the fluid flow speed in an opening in the wall of the tank is called Torricelli's law.
Depending on the bottle diameter, the drip interval will steadily decrease with a different rate,
because the water level in the bottle will go down until its equal to the outlet level and the dripping
stops completely. This decrease of frequency can be used to achieve nice strobe effects.
Firing the flash or triggering the camera with a constant interval similar to
the initial drop interval will result in capturing the drop in different phases.