Rob,Originally Posted by Rob O
This is a very cool shot. From your text, is sounds like you wanted the star streaks to be the subject. As it turned out, the trees are the subject, and without your info, we would all be wondering how you got the trees lit, and had star trails.
As for the low noise issue: Many of the DSLR cameras use a "Dark Slide" to get rid of noise, in long exposures. It works like this - After the initial image is done, the camera turns the sensor back on (mirror down and shutter closed) for the same or similar amount of time, as the initial shot. There will be color noise recorded on this "Dark Slide". The camera then subtracts the data on the "Dark Slide", from the first image file. It works very well, but the camera is on for a long time, and it can kill a battery, before it is finished.
Very cool, either way.