Moving from broadband to narrowband...

[900SL]

12 minutes ago, TiffsAndAstro said:

i said it first

You win

 

Hey, my HOO starless is getting there. I might have to get NoiseXterminator, I'm still struggling with backgrounds after like 7 hrs+ mono subs

 

[Elp]

What the issue with adding RGB stars back in?

[TiffsAndAstro]

19 minutes ago, 900SL said:

You win

 

Hey, my HOO starless is getting there. I might have to get NoiseXterminator, I'm still struggling with backgrounds after like 7 hrs+ mono subs

 

Ok so this is miles better than my attempt. You even got the bubble behind it too.

Also don't think I've seen two bow waves off the front of the brain before. I can't even image one of those bow waves.

[TiffsAndAstro]

1 minute ago, Elp said:

What the issue with adding RGB stars back in?

Er, tbh lining them up with a different stack background.

Pretty sure this is relatively straightforward in pixinsight, not so much in free tools.

Probably another reason I should learn full manual stacking, alignment etc.

[900SL]

2 minutes ago, TiffsAndAstro said:

Ok so this is miles better than my attempt. You even got the bubble behind it too.

Also don't think I've seen two bow waves off the front of the brain before. I can't even image one of those bow waves.

Just giving you something to aim for   I was like you on the Veil 18 months back. You should be chuffed with that, terrific improvement from the fetid bilgewater you were posting a few months back 🤣

[Stuart1971]

1 minute ago, TiffsAndAstro said:

Er, tbh lining them up with a different stack background.

Pretty sure this is relatively straightforward in pixinsight, not so much in free tools.

Probably another reason I should learn full manual stacking, alignment etc.

I think the idea is that you take all your subs through the dual NB filter, then remobe that and take some short exposures with no filter or maybe an LP filter and use those for the stars, so the scope has not been moved inbetween…then they will line up when you add them back as long  as they are cropped using the same crop as the other light frames…

Edited Friday at 16:29 by Stuart1971

[TiffsAndAstro]

Just now, 900SL said:

Just giving you something to aim for   I was like you on the Veil 18 months back. You should be chuffed with that, terrific improvement from the fetid bilgewater you were posting a few months back 🤣

I still like my veil 4 panel

[Elp]

If you've done it a few times is a 1-2 minute job in PS/GIMP, I align all mine manually.

[900SL]

6 minutes ago, Elp said:

What the issue with adding RGB stars back in?

When I use starnet in Siril on the linear image, it extracts the stars no problem but trying to stretch the starmask  so they look OK is impossible, the histogram is rammed up hard left

[Stuart1971]

Just now, 900SL said:

When I use starnet in Siril on the linear image, it extracts the stars no problem but trying to stretch the starmask  so they look OK is impossible, the histogram is rammed up hard left

Alter the scale on the histogram until it moves away from the left side…

[TiffsAndAstro]

Just now, Stuart1971 said:

I think the idea is that you take all your subs through the dual NB filter, then remive that and take some short exposures with no filter or maybe an LP filter and use those for the stars, so the scope has not been moved inbetween…

Yeah taking the data is the easy bit.

I can stack RGB and dnb separate then extract stars and put back RGB ones only. But no guarantees they will line up exactly. Maybe close enough no one will notice, but that doesn't seem proper

[Elp]

I usually do minor stretches to the stars, hard saturation, then do a star minimisation to reduce their sizes back down.

I think @ollypenrices method he outlined a few months back will work well.

[TiffsAndAstro]

2 minutes ago, Elp said:

If you've done it a few times is a 1-2 minute job in PS/GIMP, I align all mine manually.

You mean by eye?

Another reason I should learn gimp layers. Small icons though

[Stuart1971]

Just now, TiffsAndAstro said:

Yeah taking the data is the easy bit.

I can stack RGB and dnb separate then extract stars and put back RGB ones only. But no guarantees they will line up exactly. Maybe close enough no one will notice, but that doesn't seem proper

Is there no star alignment tool in siril…Get pixinsight, you will end up with it anyway at some point….😂😂

[TiffsAndAstro]

Just now, Stuart1971 said:

Is there no star alignment tool in siril…Get pixinsight, you will end up with it anyway at some point….😂😂

I think, after a better mount pixinsight is next on my list

[900SL]

2 minutes ago, Stuart1971 said:

Alter the scale on the histogram until it moves away from the left side…

Even on 100 it is still hard left, I think it is Starnet when working on a linear image. It applies a basic stretch but I might try adding a arcsine stretch before using starnes

[Elp]

Just now, TiffsAndAstro said:

You mean by eye?

Another reason I should learn gimp layers. Small icons though

Yes. I use star images beneath for reference, then align any other layers on top. If aligning starless, it's a similar process, by blinking top layer visibility on and off a few times you'll see on a pixel level whether you're off, adjust position with an arrow key press and repeat. It really doesn't take long at all after practice.

It helps a lot if you use the same camera and optics, I've often done it with 2-3 different cameras and difference lenses and scopes and they still align fine after scaling and rotation operations.

[900SL]

3 minutes ago, Stuart1971 said:

Is there no star alignment tool in siril…Get pixinsight, you will end up with it anyway at some point….😂😂

You can register separate images in Siril to align frames. It's quite sophisticated, it will warp, scale, etc to match

Edited Friday at 16:36 by 900SL

[Elp]

Can also use LRGB composition but it wont work with starless images.

[TiffsAndAstro]

1 minute ago, 900SL said:

You can register separate images in Siril to align frames

I'm sure it's possible. On my list to learn

[Stuart1971]

I know many people see Pixinsight as being expensive and I agree, but the tools in it are priceless really, and when we spend thousands of pounds on kit to get the images, a couple of hundred more to really process them to there full potential, is nothing really…why skimp on the last bit of the puzzle in this hobby…and it really is not that hard to use…but that’s just me..

[TiffsAndAstro]

1 minute ago, Elp said:

Can also use LRGB composition but it wont work with starless images.

This is my plan for my reason detre, the horsehead nebula.

Will also try hh in dnb too of course

[Stuart1971]

I’m actually not a fan of processing my images at all, it’s not the bit I really enjoy, I am a tinkerer, and love the hardware side of things, so anything to make processing easier and less tedious, is always good for me

[Elp]

4 minutes ago, 900SL said:

You can register separate images in Siril to align frames. It's quite sophisticated, it will warp, scale, etc to match

I did this recently having wisely (not) used a different camera so the pixel scales were different. Had to re-export all sessions with their own calibration frames applied, exported as individual images, then load every image together at once register etc.

It pushed me to getting another HDD now as the 2TB is full.

[900SL]

3 hours ago, Stuart1971 said:

Alter the scale on the histogram until it moves away from the left side…

OK, now I'm getting somewhere. I did a gentle arc sine stretch on the RGB stars, and increased saturation, taking care not to blow out stars. Then ran Starnet 2 on the HOO image and dumped the HOO stars, and then same on the RGB stars, but kept the stars. Then used the Siril Star recombination.

Feel free to laugh at the consequences of not making sure the framing was accurately matched each night. This is just a rough pass to see whether it would work.