That comet pic is not bad actually but I'd still want to stretch the levels. I reckon it's comparable to film.
I did some experimenting last night, just out the front of the house and found something very weird. All exposures were set to the max 15 seconds. It doesn't seem to matter much where you set the ISO levels, be it 64, 200, 1600 or whatever, if you stretch the levels in photoshop to look the same brightness for each pic, the noise level turns out the same! In fact the 64-200 ISO frames had more hot pixels than the ISO 1600 frames! That ain't right is it? There's something screwy going on here.
