brusspup March 11 2013 (Thanks, Dale)
Ever since I created the first version of this video a year ago I’ve been wanting to try it again with more water and better lighting / footage. This is a really fun project and when you first see the results, chances are your jaw will drop. The main thing to keep in mind for this project is that you need a camera that shoots 24 fps.
The effect that you are seeing can’t be seen with the naked eye. The effect only works through the camera. However, there is a version of the project you can do where the effect would be visible with the naked eye. For that project, you’d have to use a strobe light.
For this project you’ll need:
- A powered speaker
- Water source
- Soft rubber hose
- Tone generating software
- 24 fps camera
- Tape
Run the rubber hose down past the speaker so that the hose touches the speaker. Leave about 1 or 2 inches of the hose hanging past the bottom of the speaker. Secure the hose to the speaker with tape or whatever works best for you. The goal is to make sure the hose is touching the actual speaker so that when the speaker produces sound (vibrates) it will vibrate the hose.
Set up your camera and switch it to 24 fps. The higher the shutter speed the better the results. But also keep in the mind that the higher your shutter speed, the more light you need. Run an audio cable from your computer to the speaker. Set your tone generating software to 24hz and hit play.Turn on the water. Now look through the camera and watch the magic begin. If you want the water to look like it’s moving backward set the
frequency to 23hz. If you want to look like it’s moving forward in slow motion set it to 25hz.
will this experiment work with a camera and speaker set at 20 fps and 20 hz, or 30 and 30? if not why does it have to be 24fps? Thank you, Jim
I don’t know the answer to your question, Jim. You might want to send a message to the creator of the video. Blessings, g
This demonstration seems easily explained by:
1) Speaker motions move the tip of the hose in a circular direction, causing water to cascade down in spirals.
2) The camera exposure rate captures water droplets at different stages in its cyclical descent. Capturing the water at slightly earlier or later stages of its spiral (cyclical) descent is accomplished here by adjusting the water’s cyclical period (by adjusting how fast/far the hose tip moves, by adjusting sound frequency).
Thanks for the explanation, Paul. Blessings, G