I've successfully done some star trail photos with seemingly no noise (or not noticeable) without going through Noise Ninja or anything. However my last time out I was a bit rushed, and had my ISO at 200 instead of 100. I didn't think it'd be a big deal... but do you think its responsible for all the noise in the image below? I also did exposures of 40 minutes instead of around 20 or so in the past. Would doubling the time, and leaving iso @ 200 really have such bad results?? 100% crop here here's an example of one of my older files (below- it's a little soft due to focusing past infinity, but no noise). I think at iso 100, but I wouldn't have though jacking to iso200 would do so much damage as to cause the noise in the images above... Any tips/thoughts would be appreciated.