For this image of SH2-124 I used some new techniques which I am happy to share below.
Also, it is my first image acquired with N.I.N.A. After two years happily working with ASIAIR, I wanted to learn about N.I.N.A. N.I.N.A. is powerful and gives you a lot of control about what you are doing, which is good. On the other hand I found myself spending much more time preparing the observation and experimenting than with ASIAIR - without any visible improvement in the images. So I am not sure if its worth it. Also, N.I.N.A. only runs on Windows, as opposed to a Raspberry PI or a plain and simple Linux server - what a waste of resources. I might get back to ASIAIR at some point.
As usual I took three images in Halpha, SII and OIII. I combined the not yet stretched images with pixelmath in Siril like this:
- RED: 1.5*(0.9*S + 0.1*H)
- GREEN: 0.2*H+0.8*O
- BLUE: O
Dont ask me why I did this, I just found that the results are good
Afterwards I subtracted the stars in the unstretched color image with starnet++. Since the image was still linear, Siril first stretched the image, subtracted the stars and undid the stretching afterwards.
In the next step I stretched the starless image, applied Sirils new and cool noise reduction algorithm and did a GHS on it.
The next step was to add the stars back in with pixelmath. BUT I used the linear image of the stars for this. I order to make the combined image look OK I had to apply a factor of 120 to the image with the stars. Combining a stretched starless image with an unstretched star mask is kind of a wild hack, but it looks good in my eyes.
There are some artifacts of the imperfect star removals in the image. So I will continue to search for other ways to get an image with similarly good-looking colors.
Finally, as usual, I used Rawtherapee for post-processing with a little tone mapping and blackness and color saturation adjustments.
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