Two images of the same part of sky and same exposure taken 4 minutes apart show how the cloud has changed, and how the light level has dropped. Sun dropping to 9.1 degrees below the horizon. Images by Nicky Fleet.
Click here for an animation (1.7 MB gif) 19 images over 4 minutes
Another pair of equal exposures 7 minutes apart of almost the same part of the sky. The higher cloud patterns disappear into the shadow while the whiter ones lower down become more distinct. Sun dropping to 10.1 degrees below horizon. Images by Nicky Fleet.
Click here for an animation (2.5 MB gif) 32 images over 7 minutes
Almost simultaneously with another camera pointing more to the west. The descending shadow is more obvious in the wider angle view of this pair of equally exposed images. Sun dropping from 9.6 to 10.1 degrees below horizon.
Click here for an animation
(1.8 MB gif)
29 images over 6 minutes
Canon EOS 20D and 400D 21st July 2009