The time-lapse sequences in the SALT documentary were shot with a simple Digital SLR camera. Thousands of normal still frames were shot over a period of time then assembled in sequence and played back at 25 frames per second. Sometimes the camera was placed on a ‘panning table’, a small moving head that could be timed to move in sync with the shutter, allowing the angle of view to change through the sequence.
Having never attempted anything like this before, there were many problems to overcome. Firstly, the camera and the panning head had to be powered for the duration of the trip onto the Lake. After a crash course in electrical circuits and soldering, 80 camera batteries were wired together to run the small system.
Danny Gailbraith at Geosciences Australia assisted with astronomical data as it was necessary to determine the exact points and timings of the sun and moon rising and setting for the time-lapse sequences.
That then required the correct mathematical calculations to get the right number of shots to match the moving panning device.
Finally the correct exposure had to be set for the duration of the time-lapse. This varied wildly according to the phase of the moon and the direction the camera was pointed on each set. It was all trial and error and there were many failures. But, one advantage of such a long project is that there was ample time to keep experimenting with, and refining the technique.