@mwichary checkout the times for the nightly illuminations of the #LaPaDu Landschaftspark in Duisburg. If you are interested in #Lightpainting, you might see some lightpainters there, perhaps they even answer your questions.
If you are near Karlsruhe in August, do not miss the #schlosslichtspiele https://www.schlosslichtspiele.info/
And if you like old vehicles and have some time left, try https://fahrzeugmuseum-marxzell.de/ nearby - no educational attempts, just barns filled with a lot of stuff.