Robin,
As Steve said, it's difficult to tell too much from the < 200KB images stored as attachments, but a few comments:
- you will only get about a 1.7 times reduction in noise from 3 times the exposure - sqrt(3)/sqrt(1)
- M8 is a pretty bright target, so the S/N is fairly high to start with. Reducing it by 1.7 times may not be that noticeable.
- Have that fiddle you mentioned. Processing will make a difference so maybe you can squeeze a bit more out of the longer subs
- Have a close look at the background. Any difference in noise will be more visible there
- Try stacking them all together. You might get a small improvement from that
Cheers,
Rick.
|