I gave a bit longer answer here: https://lemmy.world/comment/17856195

But basically postprocessing and image staking allows you to use high iso with minimal quality loss

Yea sorry I thought it would be easier to say German because not everyone knows where Franken is.

Should have put it in the description

If you’re only taking a single exposure then yes lower is better (when shooting a static scene from a tripod)

But I have taken multiple exposures and combined them in post so the noise averages out.

Also the stars move so there’s only so much light I can capture and I would need to boost the exposure in post that would also then increase the noise.

As for the foreground, I was cold and didn’t want to wait 8min extra so I used a bit more ISO.

The real world difference between low and higher ISO isn’t as bad as it seems in the datasheet, especially when you throw postprocessing in the mix