What kind of exposure is needed for ISS flyover videos?

[Pengwuino]

http://eol.jsc.nasa.gov/Videos/CrewEarthObservationsVideos/

I saw one of these videos and they seem pretty badass. However, I was wondering, does anyone have any idea of what kind of exposure you need for those kinda videos? I'd be speechless if the exposures were the usual fraction of a second exposures you normally do and just compiles together to run at the 24-30fps. I imagine they may be a few seconds exposure, but I don't know :)

DISCUSS!

 

[micromass]

Wooow, very nice videos! :!)
I'm impressed peng!

 

[Ben Niehoff]

To get a good guess at the exposure, look at the stars in the background. The stars are quite faint, and do not make long streaks (but since it is video, I can't tell if they make short streaks). So the exposure can't be longer than about 10 seconds.

I can't guess what ISO the camera is using, but it seems reasonable that to get the city lights to show up brightly at that distance would be something on the order of 2-3 seconds at ISO 800 (assuming an aperture around f/2.8).