A lazy man’s Sadr and Crescent in SHO

[Icesheet]

I haven’t had the motivation for imaging (or processing) recently but collected some wide field data around Sadr and the Crescent nebula with my ZWO ASI 2600MC and Takahashi FS-60 with reducer for the first time. There is issues with tilt and/ or spacing that need addressing at some point. 
 

This was a very lazy capture and process. No calibration frames, automatic background extractor on PixInsight. Used the STF function for the stretch and used Bill Blanshan NB normalisation process to create a Hubble palette from the L-extreme data. Stretched the RGB stars separately and added back with PixelMath. Think I might just take the lazy route from now on! Not sure the time I normally spend would improve this much. 
 

30x300s with L-extreme

20x180s RGB

Edited December 8, 2022 by Icesheet

[old_eyes]

Looks pretty damn good for the 'lazy' process!

[Icesheet]

Thanks, if I can get away with it the lazy way will be the future for me!

[The Lazy Astronomer]

A person after my own (lazy) heart!!

Nice dusty region this, and l think l spy (faintly) the soap bubble as well. 

What pixelmath did you use to extract and add stars back, they look possibly clipped to me?

[Icesheet]

Yeah it's there, faint as you say. A little clearer in the starless version. Actually I had issues with my stars in both the l-extreme and RGB data. L-extreme had halos and I think I blew out the stars in my RGB with 180s exposures. Perhaps that's why they are clipped? In any case I removed the stars using star net and just used the simple 'starless + stars' in pixel math. I'll take a look at the RGB stars again. See if I can get more natural colours.

[The Lazy Astronomer]

1 hour ago, Icesheet said:

starless + stars' in pixel math.

That'll be the culprit l reckon. A good way I've found is use an unscreening and rescreening technique:

1. Do all your normal processes up to star removal, then duplicate the image and run starnet (or starX, whatever you use) on one, but don't ask for it to make a stars only image.

2. In pixelmath, do:

~((~original)/(~starless))

This will give you your unscreened stars image

3. Process your starless and the unscreened stars images however you desire, then rescreen the stars back in with pixelmath:

~((~starless)*(~stars))

[Icesheet]

1 hour ago, The Lazy Astronomer said:

That'll be the culprit l reckon. A good way I've found is use an unscreening and rescreening technique:

1. Do all your normal processes up to star removal, then duplicate the image and run starnet (or starX, whatever you use) on one, but don't ask for it to make a stars only image.

2. In pixelmath, do:

~((~original)/(~starless))

This will give you your unscreened stars image

3. Process your starless and the unscreened stars images however you desire, then rescreen the stars back in with pixelmath:

~((~starless)*(~stars))

Thanks! I'm not sure I have followed this as you intended as the stars were coming from the RGB image and the starless from the l-extreme image but I have given it a go. I was also a little less aggressive in the starless processing and left more stars in but overall this is probably a more balanced version. Now I wasn't so lazy though 😆

Let me know if you think I have followed this correctly. Appreciate your input!

 

[scotty38]

Very nice! More stars = better, in my opinion anyway 😀

Edited December 9, 2022 by scotty38

[The Lazy Astronomer]

Yep, stars seem to be sitting much more naturally in that one. Maybe for my taste they're a little too prominent, but everyone has their own opinion on how starry images should be!

[Adam J]

On 09/12/2022 at 09:01, scotty38 said:

Very nice! More stars = better, in my opinion anyway 😀

Yes I agree, I find the stars are part of them image where as some see a nice starfield as a blemish.