20 January 2021: Soon to be released APP 1.083-beta2 : improved comet registration, updated tools, new Star Reducer Tool and more...
16 November 2020 - Wouter van Reeven has officially joined the Astro Pixel Processor Team as a moderator on our forum, welcome Wouter 🙂 !
Green cast on final integration with duoband subs
Hi, apologies if this has been answered in another forum but I cannot find the answer. I am new to OSC processing in APP. I keep getting a significant green cast across the whole frame in the final integration regardless of what setting I choose in step 0, I have checked and unchecked force cfa devayer, tried both AAD and Ha-Oiii-color algorithms and they show no diff with strong green cast. I can however use the Ha extract and the Oiii extract algorithms successfully and later combine them into HOO bicolor but I can’t understand why I am getting that strong green cast. See attached photos. I have also included the Ha and Oiii separate integrations which seems fine in mono.
@7imlooigmail-com Hi Tim, do you also get the green cast when you enable Neutralize-BG in the upper right? What camera are you using? And what software to shoot the images? What calibration files?
@wvreeven I haven’t tried to check the neutralize-BG in the normalization step 5 yet, will try that, am using darks, flats and dark flats cal subs. Using asi183MC pro and acquisition in asiairpro. In asiairpro the subs were not showing green cast in RGB tho see photo attached
@7imlooigmail-com I didn't mean Neutralize BG in tab 5 but the checkbox once the integration is done. See the checkbox that the red arrow is pointing to in this screenshot:
@wvreeven ah that fixed it, thank you. Is this something we need to do all the time with duo-narrowband filters? Just trying to understand where the green is coming from, cheers
@7imlooigmail-com To be honest, I am not quite sure myself. OSC have twice the amount of green pixels than red or blue and that certainly accounts for part of it. But the OIII signal is much fainter than Ha so I'd expect a more or less neutral background to begin with. But I see it in my pics as well so perhaps there is a lot more green noise than red or blue which causes this effect. In any case, I'm glad that neutralizing the background like that worked.