This photo was taken from the hillside trail overlooking the Fountain Park.  It was a single exposure at f/2, 123 seconds, ISO 100, with a focal length of 24mm, but the RAW file was processed twice in order to get the nice orange glow just above the horizon.  This area was blown out otherwise.  I also masked portions of that darker layer to darken other areas of the foreground making the saguaro more prominent.  The white “dashes” in the sky are the beginnings of star trails.  I’m a little surprised that they are visible through the clouds.