I've taken a few photos with the D800 at night and just wanted to share some real life samples of how the D800 handles noise. There's a lot of scientific tests out there so I wanted these images to reflect more on real life scenarios, they've all been post processed with noise reduction. I had taken some snaps using the HI settings but I found them pretty ugly because of the colour cast and the amount of chroma noise it generates (under low light conditions). Some samples on the net suggests that the HI settings on D800 is perfectly usable after NR and sizing down but they were probably taken under bright light. These were taken around streets of Brisbane under mixed lighting conditions. Overall I'm very impressed by the D800 ISO performance .
1. ISO 800
2. ISO 2000
3. ISO 3200
4.ISO 6400