[DiscoDuck (Paul)]

Originally Posted by alpal

Nice picture Paul.
Photoshop can clean up that noise by using a blurred layer mask -
reducing the colour selectively in each channel, and adding noise.

see here but use a mask so you don't add noise to the galaxy:
http://bf-astro.com/backgndrepair.htm

Note: you can do better than the link by selectively doing it to each color channel.

cheers
Allan

Thanks Allan. Will try that. Much appreciated.