I have a Baader 1.25 inch narrowband set, SII at 8nm, Ha at 7nm and OIII at 8.5nm. I am used to image with an ASI1600MM-Cool at 200 gain / 50 offset, using 2 minutes exposures at f/4.
With SII I usually get 250-400 ADU above bias, with Ha 350-500, with OIII 650-800. If I compare the exposures from the 3 filters, OIII is always noisier and often shows background gradients, especially if I don't integrate much data. I image from a light polluted sky (bortle 6/7)
The Baader OIII ultra narrowband at 4.5nm started to get my curiosity.... will going narrower solve/reduce my problem? Will I be able to combine SII 8nm, Ha 7nm and OIII 4.5nm without visible issues?
A last question: how's the Astronomik OIII at 6nm? I might try a completely different brand at this point.
Edited by Epox75, 27 June 2020 - 11:11 PM.