Taken last night with a very big moon so I kept the subs to 2 minutes, ISO 800 with my Canon 60Da. Shot with my W/O Flt 110, 1 hour stacked in DSS and processed in photoshop.
It has been about 4 years since I last shot this and I remember why I loved it then.
Nice image Mark. You were possibly limited by the two minute subs but it would be worth trying to extract a little more with a small curves adjustment.