Fantastic shots, especially the silhouette of the IB climbing out! DUS looks like an excellent airport for spotting/photography judging by that lot. Lots of good vantage points, or is there a well placed viewing terrace or something?

Well DUS has 2 good viewing terraces. One is on the airport railway station and one on the main terminal. The good thing is that one is on the eastern end and one near the western end of the main runway and both are facing more or less to the north. So you get a good chance nearly the whole day, regardless of wind conditions. It costs 2 Euros for a whole day of access on both terraces, including transfer with the airports skytrain service.

And there are a lot of spots arounf the perimeter that are also usefull. But only the terraces offer perfect coverage of take-offs and landings on both runways.