Combining OSC star colours with L-Extreme dual band nebulosity?

Questions and answers about processing in StarTools and how to accomplish certain tasks.
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

I would like to achieve the above, but I know not where to start! Is this even possible? Is it a case of using the L-extreme data as the Lum and somehow stripping out the RGB channels from the broadband colour data then doing something clever with masks? Any tips appreciated.
Thanks, Andy
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

Ok so I have found a thread suggesting I process both separately, which I have done, then bring into the layer module (L-extreme as background) then create a star mask and blend using colour of FG. Trouble is, with the star mask as-is, I don't get the foreground star colours - the only way I can is to invert the mask, but then I lose the nebulosity colour & detail. My understanding of layers and blending is a weakness I've taken through with me in every processing tool I've ever used, so I am hoping there is a simple remedy to achieve what I'm after.

(I took screenshots but no matter how small I save the jpeg it says they are too large!)
hixx
Posts: 167
Joined: Mon Sep 02, 2019 3:36 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by hixx »

Hi, please check the inofficial guide ( available on download page: https://www.startools.org/downloads/uno ... sh-manual-
page 44 has a method to process stars independently, also to be found on Guy's excellent user notes there is a special techniques index: viewtopic.php?f=12&t=2505 - this has also some tricks for Compose to add narrowband data to RGB.
There are some fancy tricks you can achieve with Layer, Mask, Compose. But how about processing real RGB, so you'll get the star's Lum & color and then simply loading l-enhance into Narrowband slot - this allows you to easily throttle affected narrowband areas.

cheers,
jochen
almcl
Posts: 232
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by almcl »

Not sure which thread you found, but if it was this one

viewtopic.php?f=4&t=2003&p=8776&hilit=RGB+stars#p8776

then the process used was to extract the RGB stars and save them, possibly with increased saturation.

Create a mask of just the stars and save it. Now load the LExtreme data and check if the mask you created is actually covering the stars. Mine needed a bit of adjustment via offset x & y.

Once it is aligned, then with the mask still active, launch the layer module, open the stars only file and set layer mode to color of fg. Adjust blend amount to taste to give required star saturation.

Apologies if you already tried all this, let us know if you are still having issues?
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

almcl wrote: Mon Feb 28, 2022 10:12 pm Not sure which thread you found, but if it was this one

viewtopic.php?f=4&t=2003&p=8776&hilit=RGB+stars#p8776

then the process used was to extract the RGB stars and save them, possibly with increased saturation.

Create a mask of just the stars and save it. Now load the LExtreme data and check if the mask you created is actually covering the stars. Mine needed a bit of adjustment via offset x & y.

Once it is aligned, then with the mask still active, launch the layer module, open the stars only file and set layer mode to color of fg. Adjust blend amount to taste to give required star saturation.

Apologies if you already tried all this, let us know if you are still having issues?
Hello, thanks for the reply, yes the method you suggest is exactly what I was going. I think the mask is the issue, I need to tweak it a bit more but it's difficult as it keeps blotting out nebulosity in the process. Onus is on me to learn to use it properly!
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

hixx wrote: Mon Feb 28, 2022 8:02 pm Hi, please check the inofficial guide ( available on download page: https://www.startools.org/downloads/uno ... sh-manual-
page 44 has a method to process stars independently, also to be found on Guy's excellent user notes there is a special techniques index: viewtopic.php?f=12&t=2505 - this has also some tricks for Compose to add narrowband data to RGB.
There are some fancy tricks you can achieve with Layer, Mask, Compose. But how about processing real RGB, so you'll get the star's Lum & color and then simply loading l-enhance into Narrowband slot - this allows you to easily throttle affected narrowband areas.

cheers,
jochen
Thank you Jochen, I will read the manual today, but when you say process real RGB, I mine is from a OSC so do I load it 3 times into each RGB slot plus the L-extreme data in the Lum and NB accents slot or just the NB accents?
hixx
Posts: 167
Joined: Mon Sep 02, 2019 3:36 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by hixx »

If you load OSC / DSLR data with linear, not white balanced (2nd option) it will by default start Compose module, loading red pixels to R, green pixels to G and blue pixels to B. So you only need to load this once for RGB. You may add another L file of course or create synthetic L from Compose options.
You could use L-extreme for L to create more contrast between Ha / OIII regions and stars for example. Or you may add L-extreme to NBA slot to enhance nebulosity
cheers,
jochen
almcl
Posts: 232
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by almcl »

Notty wrote: Tue Mar 01, 2022 9:04 am
I think the mask is the issue, I need to tweak it a bit more but it's difficult as it keeps blotting out nebulosity in the process. Onus is on me to learn to use it properly!
If you extract the stars as per the first part of the procedure here
viewtopic.php?f=7&t=244

taking care not get too much nebulosity then create the mask from the 'stars only' image, go into layer module and load the LExtreme image, swap background and foreground, you may find this helps?
Skywatcher 190MN, ASI 2600 or astro modded Canon 700d, guided by OAG, ASI120, PHD2
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

hixx wrote: Tue Mar 01, 2022 1:53 pm If you load OSC / DSLR data with linear, not white balanced (2nd option) it will by default start Compose module, loading red pixels to R, green pixels to G and blue pixels to B. So you only need to load this once for RGB. You may add another L file of course or create synthetic L from Compose options.
You could use L-extreme for L to create more contrast between Ha / OIII regions and stars for example. Or you may add L-extreme to NBA slot to enhance nebulosity
cheers,
jochen
Now that is useful info, thank you!
Notty
Posts: 23
Joined: Mon Jan 23, 2017 8:51 pm

Re: Combining OSC star colours with L-Extreme dual band nebulosity?

Post by Notty »

almcl wrote: Tue Mar 01, 2022 5:53 pm
Notty wrote: Tue Mar 01, 2022 9:04 am
I think the mask is the issue, I need to tweak it a bit more but it's difficult as it keeps blotting out nebulosity in the process. Onus is on me to learn to use it properly!
If you extract the stars as per the first part of the procedure here
viewtopic.php?f=7&t=244

taking care not get too much nebulosity then create the mask from the 'stars only' image, go into layer module and load the LExtreme image, swap background and foreground, you may find this helps?
Just read that, thanks, that looks a great little technique, but when I create my mask there's no option to exclude specific colours? Just "include only", maybe that feature has been removed since 2012?
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