Here is a short music video featuring two wide-angle time-lapses of the August 21, 2017 total solar eclipse. I shot these under very clear skies in the Teton Valley of eastern Idaho. The peaks of the Tetons in Wyoming are at left in the frames.
WHAT TO LOOK FOR:
The time-lapses record the Moon's shadow sweeping across the sky. As the song says, "We were being followed by a moon shadow."
I present two sequences:
The first with a 12mm full-frame fish-eye lens, and the second with a more conventional but still very wide 14mm lens. Both show the Moon's umbral shadow sweeping in from the west at right and moving quickly across the frame to engulf the Sun at the start of totality. Look for the wave of blue darkness moving in. That's the umbra.
The shadow then moves off to the east at left, to bring totality to sites farther down the path. As the dark blue shadow departs, the Sun reappears from behind the Moon in the diamond ring effect.
Note how the most colourful area of horizon twilight remains to the south. And that the advancing edge of the shadow seems more distinct than the receding edge. Had there been clouds in the sky (no thanks!) we would have seen the shadow more clearly defined as it darkened and brightened the clouds in a wave across the sky. Those who had broken clouds would have seen this effect.
Both sequences were shot as time-lapses at 1 frame per second and consist of 650 to 700 frames. I started each about 5 minutes before the start of totality and ended them about 5 minutes after the end of totality. The cameras were on aperture priority auto exposure with a -1 EV exposure compensation. The shooting techniques were discussed in my eBook How to Photograph the Solar Eclipse.
I developed the frames in Adobe Camera Raw and LRTimelapse. The processed frames were rendered at 30 frames per second, but with two "tweened" frames added between each frame to smooth the motion more, and make the shadow motion less rapid. Even so, it was moving at hundreds of kilometres an hour. The plane you see at the end of each sequence couldn't hope to catch, let alone keep up with the shadow!
PS: Excuse the banding and posterization created by the movie compression. Twilight skies are the hardest subjects to depict and suffer from any image compression.