Here's a first picture with an Astronomik CLS filter. It's one light frame (1 minute, f2.8, ISO800), dark frames subtracted and then just stretched. It's not far above the horizon. I deliberately made it lighter than I normally would so you can see the colours. The sky comes out green blue instead of red brown and I'm sure I can expose for much longer without the sky getting too bright. The brightest stars are blown out though.
What doesn't really show in the full picture is the colours of the stars. At full size they are quite blue and green with red fringes around the bright stars. I've attached a 100% crop. If I try and achieve a neutral colour balance I end up with pink stars. Same thing happens if I try background subtraction.
Any tips on processing these images?