About 2 hours and more than 500 shots later I finally did it: I shot lighting! One needs patience, lots of nerves and luck. I didn’t readup on how to do it before, but in the end I pretty much figured it out. The full battery ran out, that much I was using the camera.
Exposure time is not so important, especially when you are exposed to the light polution of the city. I kept it low, from 6 to 10 seconds. I tried with 30 seconds (maximum) but it was just to bright.
What I found, is that getting the Aperture correct is the way to get it right. Increase it when the storm is further way, decrease when it’s closing in. In the end, when the storm reached our block of flats, I did set it around f/5.6 and f/6.3. This was good. I was continously shooting every 6 seconds keeping the trigger down (didn’t have my cable handy).
Except for the camera technique, there were a few more challenges, e.g. the actual danger when the storm got closer: keeping windows open is no good. Also the incoming rain was making everything wet. Great fun however, even though only 20 shots did contain actual lighting.