During my studies for my Graphic Design diploma, Photography 101 was a required course, and that was the start of my passion for photography. After years of experimenting and just plain having fun, I've found time-lapse to be my favorite form of photography.
It wasn't too long ago that I discovered "star trail" photos. They're most commonly made from multiple photos of stars shot from a fixed position and later merged into one image. After trying this technique a few times, I wondered what it would look like with time-lapse sequences I had shot during the day.
My first few tries produced some interesting results, but looked a little too "busy" or "abstract." A little experimenting with choosing the right sequences and number of shots resulted in exciting images.
Living on the shore of Lake Ontario, just east of Toronto, facing the west, has resulted in quite a library of sunset time-lapses. These were the first subjects of my experimentation with this technique.
I call the images made with this technique "timestacks." To make them, I use a time-lapse sequence as my source. Timestacks are really a distillation of a video into a single picture. The movements of clouds often look like brushstrokes and give the image a painterly feel. It gives you a different perspective of time and a unique sense of motion.
I usually set up time-lapse shoots with the intention of producing a video as the end result. Timestacks are a nice opportunity resulting from the time-lapse sources with the right subject and settings.
My time-lapse sequences are usually multiple photos taken from a fixed position. You can use an external intervalometer to control the camera, or your camera may have that capability built in. If you have a Canon EOS DSLR, you can load software to perform the function. More about that later.
The interval between shots can change the look of the final image quite a bit. The shorter the interval between shots, the smoother the movements will look. I usually shoot in the range of 3 to 6 seconds during the day. I load my photos onto the computer and open the first one in Photoshop, making adjustments for color and contrast while recording my actions so I can apply them to all the photos. I highly recommend using an automated process for this, as it will save you time, but mainly a lot of tedious work.