Intervalometer and Time Lapse Photography
As its name implies, an intervalometer is a device that performs a specific function at regular intervals. In digital cameras, an intervalometer makes it possible to automate the process of taking tens, hundreds and even thousands of pictures without us even touching the camera. It makes Time Lapse Photography a lot easier.
Time Lapse Photography is the process of taking several photos, then making some kind of movie by combining them. The subject of the photos might be a blooming flower, a building being constructed, or somebody’s face as it changes over time. Time lapse photography is certainly possible without an intervalometer, and it is even impractical at times, when you want to take one picture per day, for example. So don’t panic if your digital camera doesn’t have an intervalometer, because you can have fun with time lapse photography, intervalometer-free!
The CHDK firmware addon for Canon Powershot digital cameras (Digic II and Digic III) adds some advanced intervalometer capabilities, either with the firmware addon itself, or through an additional script.