Hi John,
Thanks. Now that I (roughly) know what I'm doing, the next attempt will be a bit more serious.
I used Telescopious to get an idea of how the image would turn out, but haven't looked at posting any images there. I haven't considered posting my work anywhere (other than here and on my website) because I don't think it's good enough.
When it comes to exposure times I take a series of frames, usually from 10 seconds up to about 60 and then eye-ball which exposure looks the best and not too washed out. In this case, I just recycled settings from my last Eta Carina image because I knew they worked.
When I do this again I will try for longer exposures, and maybe drop the UV-IR cut filter into the mix. According to the exposure time spreadsheet I've seen over on another (American) forum, I can bump it out to 20 second exposures.
The voices in my head are saying I should do two mosaics - one with the L-Enhance to boost the Ha and a second with the UV-IR cut and combine them. I'm trying to ignore what they're saying...
Oddly enough, I tend not to use the saturation controls when processing. This one was the exception to the rule. I've seen too many over-saturated images for my liking and don't like the way they look.
Cheers,
V