15th Feb 2024: Astro Pixel Processor 2.0.0-beta29 released - macOS native File Chooser, macOS CMD-Q fixed, read-only Fits on network fixed and other bug fixes
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Good morning everyone. I have two problems: using an ASI071MC with Optlong Extreme filter, when the APP finishes its work, it gives me an image that is all red and nothing blue. What parameters should I set / flag in order not to lose the blue channel? The second problem is that when I do the calibration of the stars, the sw breaks down the colors (from very vivid to pastel and almost white); what am I doing wrong?
I look forward to your help.
Thank you
@astrolab68 Hi Dario,
When using a dual band filter like L-eXtreme, you should make change the algorithm in tab 0. If you want APP to produce a color image, you should choose Ha-OIII color. With that setting, APP will try to better separate the Ha and OIII signal resulting in slightly less noise than when using the default Adaptive Airy Disk.
However note that in nearly all emission nebulae the Ha signal is MUCH stronger than OIII. In order to make the OIII signal visible, you need to separate the Ha and OIII channels and then combine them manually. To do so, you need to choose Ha-OIII extract Ha in tab 0, perform an integration and then immediately return to tab 0, choose Ha-OIII extract OIII and perform an integration again. That way you'll get two mono images (one for Ha and one for OIII) that you can combine using the Combine RGB tool in the Tools tab.
Regarding the star colors, can you please provide a screenshot of your image before and after star color calibration so it is clear what you mean?
Thanks, Wouter
@wvreeven For now, thank you for the lesson !!! 😉 As for the image at the time of star calibration, I don't have them because I abandoned the test. Tomorrow I will try what you told me. For now, thanks. I will update the post on Friday or Saturday. Thank you
I’m not sure a star calibration routine would be valid on bicolour data, there is no yellow spectrum data recorded, only red and blue/green. When doing the rgb combine, just make sure the peaks in the histogram are aligned to give a background balance, and star cores are white with no colour tint.
Hi Dario @astrolab68 and Andy @andybooth,
Like Wouter indicates, you want to extract Ha and O3 separately using the demosaic algorithms in 0)RAW/FITS. Then create a nice Bi-Color HaO3 compositie with the RGB Combine Tool 😉 Then you are able to see the nice O3 in there as well.
Star Color Calibration does not make any sense to perform on data like this, since it is narrowband data. You need proper broadband data to do a meaningful and accurate star color calibration, that is the physics of star colors and their temperatures (Black Body physics). So yes, the Star Color Calibration Tool will not work well on data like this.
Mabula
