One of the huge benefits of digital cameras is their instant feedback. It really serves the attention span of kids. You can do things that ordinarily might require more patience to execute — like night photography. With even a cheap digital camera you can make exposures and see what you did right or wrong immediately. Then tweak. Rinse and repeat. One fun thing to try with digital night photography is lightpainting. It can be done anywhere, inside or out. Use flashlights, LEDs, light sticks or lasers to paint, outline, shade, scribble or spotlight.
It also usually requires at least a duet, one to operate camera, one to move the light, which makes it an ideal geekdad activity.
Here is one of our early attempts at painting with a green laser pointer.
I like these other examples of lightpainting found on Flickr. (Search lightpainting).