Andreas uses a manual technique of making multiple exposures and masking the hotspots. His photo's are amazing and he explains the technique on his site.

This I had to try! The results are on the right.

These are the results:

New York, the memorial lights near the WTC on 9/11:

New York, the Empire State Building on 9/11:

New York, southern Manhattan skyline:

New York, City Hall:

New York, the Empire State Building:

New York, Chrysler Building as seen from the Empire State Building:

Sony Center, Berlin:

Branderburg gate, Berlin:

Kaiser Wlihelm Gedachteniskirche, Kurfursterdam, Berlin:

Berlin, walkway behind the berlin Dom:

Downtown Miami:

Downtown Miami:

Downtown Miami next to the US41 Bridge:

Leiden City Hall:

The "De Valk" windmill in Leiden:

The Erasmus bridge in Rotterdam:

The Shell refinery in Rotterdam harbour (two wide dynamic range photograps stitched together):

The Coolsingel fountain in the center of Rotterdam: