The camera position remained the same throughout the shooting.
The frame is comprised entirely of sky. Four one hundred foot
rolls of colour film were run through the camera twelve times
each, one twelfth of the frame was exposed at every run. Each
run was divided into four second takes. Each of these was punctuated
by four second intervals which are represented by flash frames.
The four second takes are synchronised in each run so that the
flash frames at the end of each take occur on the screen at about
the same time.
The order in which each separate area of film was exposed was
dependent upon the overall distribution of clouds within the
frame. The time taken to expose each of the four rolls of film
depended on the weather conditions at the time, and varied between
one and fourteen days per hundred feet.