Geeday all,
Here's an image I did last weekend, the Helix nebula. It's not the perfect shot but about the best I could get out of the light polluted sub-frames I had to work with. I used ISO400 for this image but if I get another shot at the Helix I think ISO200 would be worth a try to pickup finer detail.
This image sets the a personal record for the longest exposure I've ever done 2hrs and 13-minutes long (38 x 3.5-min. subs).
You can see a higher resolution image here
http://www.skylab.com.au/pmsa/Helix%20Nebula.html
Paul