I've never really done any narrowband stuff, but since putting a scope in South Australia I've ad to use every clear night. So since the moon gets in the way
during a portion of the month I'v tried some NB imaging. Processing this stuff is challenging.
Here is my version of your Eta Carina nebula. It is in the Hubble palette. Man, I'd love to see this baby through binoculars!
http://www.tvdavisastropics.com/astr...s-1_000072.htm
I hope you enjoy. It does look different in this palette but the detail is quite amazing.
Tom