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[RCC] Veil Nebula

Pleiades Astrophoto PixInsight Nikita Misiura StarNet Request for feedback Emission Nebula
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akshay87kumar avatar
akshay87kumar avatar
Request your critique on the veil nebula. Among the other feedback, request you to help me understand if the star colours are too bluish. This is a set of 4 L-R-G-B (3 mins exposure each) and 4 H-O (10 mins exposure each), processed in PixInsight.
I have used LRGB Composition for the stars to create a star mask, and used the HOO for the nebula details. Here are my exact steps.

LRGB Image:
1. AstroSeti Background extraction
2. Noise Extermination
3. LRGB Recomcposition
4. Spectrophotometric Color Calibration
5. Starmask (Starnet)
6. ArcSin stretch on starmask, followed by boosting saturation

HOO Image:
1. AstroSeti Background extraction
2. Noise extermination
3. LRGB Recomposition (L=Ha, R=Ha, G and B = O)
4. Starless image by starnet
5. Generalized Hyperbolic stretch
6. Masked saturation boost

The starnet was unable to eliminate the biggest stars even on linear data (the one with spikes at the right side, noticeable in the starless image clearly), so I had to make local corrections using clone stamp and hide the artefacts using the spikes. 

Thanks for the feedback!



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Niels_L avatar
Niels_L avatar
Hi,
Stars look very blueish indeed. Maybe try a simple HT stretch on the stars-only? Also, SetiAstro has a script for star stretch that often works well (cannot recall what it’s based on). 

regards,
Niels (not the expert at all)
adrian-HG avatar
adrian-HG avatar
when i use Spectrophotometric Color Calibration on this nebula every time fail  , and  star color turn to blue or white , i dont know why….

i calibrate color  with  autocolor script or background calibration
D. Jung avatar
D. Jung avatar
Maybe try to stretch the nebula less. It looks like you lost a bit too much details and color due to that.
Remember that the highlights get compressed when you apply too high gamma. 
​​​​​​For the veil, you could try to have a partial nebula mask, excluding the bright parts and only stretching the dimmer areas. You can use the Fame or game scripts for that together with the clone tool.

To get better star color, you can always try to do it by hand. A good starting point is to take the histogram trafo and change individual colors to make RGB curves peak at the exact same area in the histogram. That's the most simple and direct way to white balance your image, known as grey-world approach.
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