Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Carole on Mar 05, 2022, 19:04:44

Title: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 05, 2022, 19:04:44
I imaged this target in 2013 at Olly's place in France.  Never been that happy with the result, so 8 1/2 years later with more processing skills, I decided to give it another go.

Luminance 12 x 900secs, Red 4 x 600secs
Green 3 x 600 secs, Blue 6 x 600secs

I don't even have the original process having had a "go" at this several times. 

This is an interim process which was cropped .
(https://www.astrobin.com/52748/0/rawthumb/qhd/?sync)


Latest reprocess:
(https://cdn.astrobin.com/thumbs/tK7g9qUAY2FT_2560x0_n1wMX-gx.jpg)

Title: Re: Praying Ghost Nebula (reprocess)
Post by: ApophisAstros on Mar 06, 2022, 07:25:54
Very nice , i do like this target for some reason , i am not sure even with more data i can improve my version , unless at a darker site.
Roger
Title: Re: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 06, 2022, 08:51:07
Thanks Roger
Title: Re: Praying Ghost Nebula (reprocess)
Post by: Hugh on Mar 06, 2022, 16:00:40
Whilst looking with my untrained eyes I do see the 2nd version as much better, I do notice that you seem to have lost a lot of background stars.  Was that deliberate or was it the magnification of the cropped one that brought them to the fore?

Hugh

Title: Re: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 06, 2022, 16:13:36
Hi Hugh,  Many imagers made the stars smaller and get rid of the tiny stars Hugh as it helps to make the Nebula stand out.  Olly taught me that, but it has taken some years to refine the process.  In fact Olly taught me a couple of processes I have used in this image. 

The stars tend to get stretched in the post-processing because you need to stretch the data to bring out the nebulosity, and the stars get stretched af the same time, so just putting them back as they were so to speak.

Some of these post-processing processes take a long time to learn so it is always good to go back and re-process old data as you learn more.  Still learning after 11 years of deep slky imaging. 

Carole

Title: Re: Praying Ghost Nebula (reprocess)
Post by: Roberto on Mar 07, 2022, 10:44:52
I like your second version a lot Carole!

Roberto
Title: Re: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 07, 2022, 14:39:00
Thank you Roberto.

Carole
Title: Re: Praying Ghost Nebula (reprocess)
Post by: RobertM on Mar 07, 2022, 17:49:58
Whilst I prefer the nebulosity of the reprocess I also find that the evenness in brightless of the background stars give it a somewhat artificial look.

Robert
Title: Re: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 08, 2022, 10:13:56
I really ought to reprocess this from scratch rather than tweaking previous processing.
Not sure if l still have the original subs and flats etc since it was so long ago. 

Carole
Title: Re: Praying Ghost Nebula (reprocess)
Post by: garrick on Mar 09, 2022, 05:38:33
The details really do come through on the second image. Great processing. Star colours are much nicer too. Really nice image.

G
Title: Re: Praying Ghost Nebula (reprocess)
Post by: Carole on Mar 09, 2022, 18:56:58
Thank you Garrick.

Carole