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How do I process LRGB?

Posted: Fri Sep 11, 2020 7:48 pm
by arrowspace90
I suspect this is another dumb question.

I have been using ST for OSC, and I have had decent results considering I don't yet know enough about post processing.

I got a Mono camera and a set of LRGB filters. I collected the lights for all and stacked with APP. Bringing the stack to ST, I confess I didn't know how to proceed, that is in any different way than with a OSC stack.
So I was not totally surprised to not end up with any color from the color module. Was I supposed to combine the RGB results in APP for color prior to bringing it to ST? Am I supposed to select a different tab in ST? Or was it all supposed to happen automatically but I screwed it up?
Obviously I ended up with the stack still in black and white.

Edit: Ok, after typing this, I see that there is a "compose" tab that I never used previously for OSC. I am not sure exactly how to set that up.
Do I bring the unstretched stack to ST from APP for each of the L-R-G-B filters so that ST knows what channel is what? After I understand what is required, I'm sure I can make this work.

Re: How do I process LRGB?

Posted: Sat Sep 12, 2020 3:08 am
by admin
Indeed, the Compose module is your friend! :)

Don't, under any circumstance, pre-composite in any other application.

Indeed, load your separate (aligned!) channels into the relevant slots and you're good to go.
The Compose module is extremely powerful. For more info on how to use it and what it does, have a look at the documentation.

Any further questions/trouble let me know!

Re: How do I process LRGB?

Posted: Sat Sep 12, 2020 7:20 pm
by arrowspace90
Well, that was a pretty spectacular failure. The image showed decent data in B&W. I don't know what happened with the RGB.
I don't know if this is an acquisition error or a processing error or both.

Re: How do I process LRGB?

Posted: Sat Sep 12, 2020 8:52 pm
by arrowspace90
However, I may be on to something here with a new style of astro/modern art. I will soon be rich.

Re: How do I process LRGB?

Posted: Sun Sep 13, 2020 3:11 am
by admin
arrowspace90 wrote: Sat Sep 12, 2020 8:52 pm However, I may be on to something here with a new style of astro/modern art. I will soon be rich.
Just don't forget the software that made you famous! :lol:

What is likely going on, is that not all channels have data for all pixels. You will want to make sure they do (use Crop).
When using the Crop and Wipe modules, use the Color button (upper right) to see what the operation does on the color dataset. Remember that your are processing two datasets in parallel (luminance/detail and chrominance/color). Wipe will even nag/tell you to please make sure you check the Color data as well before it lets you "Keep" the result.

If that doesn't yield any useful clues, please feel free to upload the R, G and B channels so we can have a look.

Re: How do I process LRGB?

Posted: Sun Sep 13, 2020 4:13 pm
by arrowspace90
I'm afraid that this first attempt for me in mono/LRGB is a bust as far as the color channels.
I must have somehow scrambled the channel data in collection or stacking.
The colors are all over the map and far from adjustable.
I had been encouraged when I saw details in the L data that looked decent. But the enjoyment ends there. For now, I have an ok black and white image that of course doesn't show much of the wonder of the area.
For my next attempt, I will leave the camera attached to the scope so the images don't get rotated. I will carefully label the L/R/B/G data as it is acquired.
Heck, perhaps trying LRGB with an F/2 RASA is just not very doable. I seem to be the only person trying it. I thought it would be a good first step before moving to the (hyper expensive) F/2 narrow band filters that are so popular. I also see a lot of people doing (hyper expensive) band pass filter imaging with their OSC cameras. I added a mono camera because I read they ultimately offer better resolution.
Lots of issues to work through. Not boring!