These days, it is not easy to obtain a minute of clear skies in the summer of 2011.

The movie shows the thunderstorm over the metropolitan area of Cologne (Germany) in the night of 18th August 2011. Actually the thunderstorm lasts 4 hours, which was enough to put together a nice video sequence. At the end of a video loop the clouds offered a short window to see the star constellations Bootes and Ursa Majoris (the "Big Dipper").

The sequence is an automatic exposure sequence, starting with automatic exposure time selection at dusk, ending with fixed setting of 30 sec exposure time during the rest of the night and a 5 second gap between every single frame. A Canon EOS 40D with a Tamron 10-24 mm wide-angle optics on a tripod was used to record the sequence. The automatic sequence timing was performed with a Canon TC-80N3 timer control. From time to time I changed the viewing direction due following some activity of the thunderstorm. The movie was created by exporting the single exposures using the Apple Macintosh software from Canon and Apple QuickTime Pro to create the MPEG-4 movie.