Lynds Dark Nebula 1251

[timastrovirus]

I left this data rest for a week before starting processing it, which still was a challenge.

Lynds Dark Nebula 1251, part of the Cepheus Molecular Cloud.

Image data was aquired during the nights of 27/28-08-2022, 1/2-09-2022, 2/3-09-2022 en 3/4-09-2022.
The Sting Of The Scorpion Observatory [TSO]2, Bortle Class 5-6.
Total 26 hours and 45 minutes (535x180 sec), gain 565, offset 25, TEC 0°C
Altair Astro Hypercam 269C PROTEC / CCDciel
Skywatcher PDS200 / MPCC MkII
NEQ6 / EQmod / CdC
QHY5 / 9x50 Finderguider / PHD2
50 darks / 50 flats / 50 bias

Pre-processing DSS 4.2.6
Post-processing PixInsight; Dynamic Crop, Linear Fit, ATrous Wavelets Noise Reduction, Dynamic Backgroud Extraction, Histogram Transformation, HDR Multiscale Tranform, Curves Transformation, LRGB combine.

 

Edited September 10, 2022 by timastrovirus

[TerryMcK]

Nice work

[timastrovirus]

I removed an anoying remnant of gradient from the center of the image, look much better I think.

[mightymonoped]

15 hours ago, timastrovirus said:

I removed an anoying remnant of gradient from the center of the image, look much better I think.

 

Yes, that's lovely! 

[Carastro]

The second version is much better.  I wonder what can have caused this weird green gradient in the first place.

Is this a colour camera?  Looks like faulty flats to me in one if the channels. 
 

Vatole

[timastrovirus]

It is a OSC camera indeed. Not sure if the cause lies in the flats, shouldn't there be issues in the other channels as well then?

 

The raw stack does have a severe gradient present, and it overlaps with most of the nebula, included the most faint parts, making it hard to remove properly without removinf true signal as well. Have a look at this STF of the raw stack to get an idea of what I am working with to start. Although I will definitely not rule out a flat issue as well, I still find it a struggle to get good flats, using twilight sky flats atm, which seem decent at least.

 

[TerryMcK]

Yes I agree the removal of the green gradient has improved the image. Have you tried the WBPP script to integrate the images/flats/darks/bias? I stopped using DSS years ago, first of all using AstroPixelProcessor instead and more recently WBPP in Pixinsight. I wouldn’t use anything else now. May give you better results and it is easy to use.