no color

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BILL_R
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Joined: Sat Oct 03, 2020 8:33 pm

no color

Post by BILL_R »

Help. I have been using older versions of Startools for many years. I just installed the latest version and am baffled. I use a one shot color camera and preprocess my images in Nebulosity4. After preprocessing, I de-bayer and stack my images. When I open the stacked image in Startools, it converts the image to monochrome and nothing I try will restore the color. What is the secret ? As far as I know, my images are de-bayered but not white balanced. Any help would be appreciated.
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Re: no color

Post by admin »

Hi,

Processing with Compose mode engaged (new in 1.5+) will see you process luminance (mono) separately to the color data. The two are combined once you hit the Color module, but until then you will be processing mostly the luminance dataset.

The are some huge advantages to this for the purpose of signal fidelity and color renditions (see here).

Opening your dataset with the second option functions as a shortcut to creating a synthetic luminance dataset from R, 2xG (e.g. re-weighted!) and B, while retaining just R, G and B for coloring.

Hope this clears things up.

If you're upgrading from something older than 1.5 you're in for a treat! :)
Ivo Jager
StarTools creator and astronomy enthusiast
BILL_R
Posts: 4
Joined: Sat Oct 03, 2020 8:33 pm

Re: no color

Post by BILL_R »

Hi,
I'm still confused.
If I have de-bayered before stacking, are there still color channels in the file I load in Startools? Should I be stacking without de-bayerting?
What is the compose mode? I see the "compose" button but it takes me to a screen to enter data about LRGB files. Since I'm using a one shot color camera I don't have any of this.
What is the second option after opening the file? Does this refer to the button next to the "linear" button that says its for digital/dslr cameras? Is this where Startools creates synthetic luminance data from the red data?
Is there any way to prevent Startools from separating the color and luminance? Is there any way to download an earlier Startools version?

I have tried both "linear" and the "digital/dslr" options when opening the file. Neither results in any color when I get to the color module. I'm sure I'm omitting some key steps but I can't figure out what to do. Any help would be appreciated.
BILL_R
Posts: 4
Joined: Sat Oct 03, 2020 8:33 pm

Re: no color

Post by BILL_R »

Hi,
I'm having trouble getting color back in my images. Can someone explain the part of the color module in the lower right corner that lists a number of codes including six or so different RGB combinations. I think these may may be there to tell Startools what color scheme my camera is using. How do I find out which one is right for my camera? ( I have tried going through the list and choosing each in succession but none of them seem to put any color in the image.)
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Re: no color

Post by admin »

BILL_R wrote: Sat Oct 10, 2020 6:50 pm Hi,
I'm still confused.
If I have de-bayered before stacking, are there still color channels in the file I load in Startools?
There absolutely should be.
Should I be stacking without de-bayerting?
Stacking without debayering wouldn't make a whole lot of sense due to the Bayer pattern being stacked out (as well as confusing the stacker's alignment algorithms).
What is the compose mode? I see the "compose" button but it takes me to a screen to enter data about LRGB files. Since I'm using a one shot color camera I don't have any of this.
Per my previous message, processing with Compose mode engaged (new in 1.5+) will see you process luminance (mono) separately to the color data. The two are combined once you hit the Color module, but until then you will be processing mostly the luminance dataset.

The are some huge advantages to this for the purpose of signal fidelity and color renditions (see here).

Opening your dataset with the second option functions as a shortcut to creating a synthetic luminance dataset from R, 2xG (e.g. re-weighted!) and B, while retaining just R, G and B for coloring.
What is the second option after opening the file? Does this refer to the button next to the "linear" button that says its for digital/dslr cameras?
Correct.
Is this where Startools creates synthetic luminance data from the red data?
This button initiates the shortcut outlined above (e.g. reweighing luminance as R+2xG+B and color/chrominance as straight RGB). It does not create a synthetic luminance dataset from just the red channel!
Is there any way to prevent Startools from separating the color and luminance?
Sure. You can use the first option, though you will obviously not be able to benefit from the enhanced signal fidelity and color rendering enhancements that processing luminance and chrominance separately offers.
Is there any way to download an earlier Startools version?
Sure! Which version are you after? Do note, however, that older versions of StarTools are no longer supported and that any documentation and tutorials will have moved on.
I have tried both "linear" and the "digital/dslr" options when opening the file. Neither results in any color when I get to the color module. I'm sure I'm omitting some key steps but I can't figure out what to do. Any help would be appreciated.
Hmmm... That sounds odd. Would you be able to upload the dataset? (Dropbox, Google Drive, Onedrive, etc.)
BILL_R wrote: Sat Oct 10, 2020 7:15 pm I'm having trouble getting color back in my images. Can someone explain the part of the color module in the lower right corner that lists a number of codes including six or so different RGB combinations. I think these may may be there to tell Startools what color scheme my camera is using. How do I find out which one is right for my camera? ( I have tried going through the list and choosing each in succession but none of them seem to put any color in the image.)
It definitely sounds like something is wrong with your dataset!
What camera do you use?

Thank you!
Ivo Jager
StarTools creator and astronomy enthusiast
BILL_R
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Re: no color

Post by BILL_R »

Hello Ivo,
Thank you for the response to my post. I appreciate the help. I think you are right about the data set problem. I have been using a qhy168c and may have the gain/offset wrong for long exposure deep sky imaging. I'll work on that problem.
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Re: no color

Post by admin »

No problem - do let us know if you'd like a second pair of eyes on your dataset.

Clear skies!
Ivo Jager
StarTools creator and astronomy enthusiast
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