The film accompanying this article was captured in Invergordon, Scotland, during July 2010 and runs for around a minute. The overall sequence took approximately 1,500 individual frames to capture over the course of 25 minutes.
I’ve tinkered with timelapse photography from time to time in the past with varying success. I’ve used a video camera to record a couple of hours of film and then re-recorded the results played back at high speed, to see the clouds gathering and dissipating around the mountains where I live. I’ve used a webcam in my office to record the progression of the day on the lake outside the company where I used to work, and more recently tried out iPhone Apps to try and capture timelapse sequences using an automated process.
Timelapse photography is fairly simple, if you understand the principle and basic technique. A camera is set to take a series of photos at a regular interval and the resultant set of images is then joined together with the results being played back at an increased rate. Usually, the frame rate is between 15 and 25 frames per second, in order to replicate a smooth sequence without flickering; this frame rate is based on the technique first identified by makers of film cameras in the last century. (A film projector usually runs at between 16 and 24 frames per second; the lower being the accepted minimum at which the human eye recognizes continuous motion.)
A video I made last summer gave me the first hint of how to better achieve timelapse sequences, when I began experimenting with my D80 digital SLR camera. Shooting at RAW quality meant that the camera couldn’t keep up with a frame rate of 1 frame per second, but as I knew that the resultant film was to be created at the standard HD size of 1280px x 720px, I fixed the camera white balance and set the exposure, then switched image capture quality to medium sized fine JPG. As I described at the time, I then put the camera onto motor drive setting and kept the button pressed down. The regularity of the D80 is great and I’ve since identified that the camera can take 1 frame per second in a sequence of 100 frames, before the buffer (temporary memory) runs out. This means that you have to release the shutter button and press it down again after the 100th frame; with practice, I can now achieve this in less than a second.
While longer sequences are possible – based on the size of the memory card in the camera and the charged battery level – I’ve been working on sequences which will result in short, 30 second film clips. At a playback frame rate of 15 frames per second, that means 450 pictures; for 25 frames per second, you need to take 750 individual pictures. Working that math backwards, you can see that a 30 second clip at 15 frames per second means you’ll be taking photos continually for 450 seconds (or 7 ½ minutes), so it’s a good idea to have the camera mounted on a tripod for this time, so that it doesn’t move and create a wobbly sequence! There are alternative options possible, to save your own finger muscles: the Sofortbild programme for Mac is excellent, if you can shoot with your camera tethered to a laptop, and I’m looking into buying an intervalometer at some point, which will go in my camera bag, save me having to carry the laptop with me, and automatically fire the camera for the sequence I need without me having to press the release manually.