Wow that sounds exciting....I have a photon bucket.....lol
Thanks guys.....the links have helped.
Chris..I have just read the link you posted with "Terry Lovejoy"
What I do find surprising is his comparison shots at different ISO's with same time exposures...their hardly any difference....If I took say 1 minute exposure at ISO 200 then the same at 1600 the difference is incredible but his shots are hardly noticeable....??????
Below are 2 x 45 second exposures of the same target M17 on the same night but with 2 different ISO's both unproccessed images resized and compressed...the brighter one is at ISO 3200 with the duller at ISO 400 I prefer the 3200 image.