Digital camera with adjustable shutter speed or exposure
I don't think that we can write in the dark
Step 1: Experiment
1.Make sure your LED light is working properly.
2.Place one LED wire on the negative side of the watch battery and the other LED wire on the positive side of the battery.
3.Squeeze the wires against the battery and the LED light should light up.
4.Repeat step 2, but this time tape the wires to the watch battery.
5.Set your digital camera to a slow shutter speed or to a setting for a long exposure.
6.Set your camera timer or have a friend take a photo.
7.Take the shot and write a message in the air using the light. Make sure the light is facing the camera.
8.Don't forget to write your letters backwards in the air! Otherwise, you are going to end up with a backwards message in the photo!