I asked Zoltán how he managed to create this captivating scene. He used the following gear and settings: Nikon D800, Nikkor 24-70 f 2.8 lens, ISO 200, f:9, 13sec exposures–except for the correct exposition of the Parliament building, which was shot at a 4-second shutter speed. The final composition was made of 61 different exposures, adjusted in Photoshop Lightroom and finally merged into a single image.
Color temperature, saturation, and contrast changes were the finishing touches. The final image you see includes approximately two hours worth of thunderstorm.
source: gizmodo.com by Attila Nagy