Author Topic: Still struggling with colour  (Read 310 times)

Offline e_ri_k

  • Newcomer
  • Posts: 7
    • View Profile
Still struggling with colour
« on: 2019 July 22 04:20:30 »
Hi guys, so I started a thread on having trouble pulling any colour out of my image. I didn't have a lot of colour data, but I now have 2 hours each in RGB and around 9 hours Luminance. After combining LRGB and Background Neutralisation I end up with just a yellow/brown image...Im running out of ideas..

Erik

Offline bulrichl

  • PixInsight Old Hand
  • ****
  • Posts: 437
    • View Profile
Re: Still struggling with colour
« Reply #1 on: 2019 July 22 05:00:26 »
Hi Erik,

only applying BackgroundNeutralization to the combined data is not sufficient. You will have to apply either the process ColorCalibration after Background Neutralization or apply PhotometricColorCalibration to the combined data (and concurrently enable PCC's Background Neutralization with 'Region of interest' checked and the Preview for background selected). For a successful plate solving that is performed in PCC, correct input of data in the section 'Image Parameters' is necessary.

I am curious: did you apply flat field correction to the light frames?

Bernd

Offline mmnb

  • Member
  • *
  • Posts: 66
    • View Profile
Re: Still struggling with colour
« Reply #2 on: 2019 July 22 11:22:04 »
Just a quick sanity check, can you post the RGB image (not LRGB) after PCC? Is there any color contrast in it?

Offline e_ri_k

  • Newcomer
  • Posts: 7
    • View Profile
Re: Still struggling with colour
« Reply #3 on: 2019 July 22 14:19:49 »
Hi, thanks for the reply. Sorry I forgot to mention, yes I did apply colour calibration to the RGB image. See below, I have posted the RGB combination with Background neutralisation, and colour calibration, and auto stretch. I don't have the PCC tool.....? I'll look into it though. Im happy to post the FITS if anyone is willing to have a go!?


Erik

Offline mmnb

  • Member
  • *
  • Posts: 66
    • View Profile
Re: Still struggling with colour
« Reply #4 on: 2019 July 22 15:29:33 »
PCC = Photometric Color Calibration

Did you also LinearFit channels before combing into RGB?

Some basic workflow on lightvortex:
https://www.lightvortexastronomy.com/tutorial-preparing-monochrome-images-for-colour-combination-and-further-post-processing.html
https://www.lightvortexastronomy.com/tutorial-colour-calibrating-images.html#Section3

EDIT: Maybe just to make sure, might be worth detailing steps you did to get image just in case there is a mistake in there. E.g. did you calibrate w flats?
« Last Edit: 2019 July 22 22:25:36 by mmnb »