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How do you colour in with a colour CCD?

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Colour processing question here. I am capturing using one shot colour CCD a ZWO 294 pro. I am finding it difficult to get the colour to show whilst processing the image. I am still capturing data on the cluster Caroline's Rose so I don't have anywhere near enough data yet to say it's complete, but I thought I would have a play around with some of the data captured last night. Out of the 30 120 second light frames only 2 of them are ok- it was v cloudy last night. 


I have attached one 120 second light frame of Caroline's rose, I haven't applied any darks or flats yet, I just wanted to see what it would look like after I debayered it in Nebulosity 4. 


Firstly it turned a sickly blue, and after adjusting the hue I was left with a very black and white looking image. I could maybe pick out some blue stars at a push, and definitely couldn't pick out any red stars. 


What am I doing wrong, and how do I improve the colour brought out in processing?

L_2019-10-14_00-52-26_Bin1x1_120s__11C.fit recon_L_2019-10-14_00-52-26_Bin1x1_120s__11C.fit

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Colour converted in Maxim adjusted saturation in P'Shop, blue stars no red ones should be some yellow ones, big gradient.




Edited by Davey-T

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You need to know the Bayer pattern of your camera. Each pixel has either a red, green or blue filter over it but which is which? Is the top left pixel, for instance, red or green or blue? Using a stellar image is not the easiest way to find out. Maybe the camera manual tells you? If so you need to set the debayerig pattern in your software to match and you should get the right colour.

In my rare forays into one shot colour imaging I've done an exposure of a multi coloured terrestrial target and simply tried all the bayer patterns (there are not that many) till I got credible colour and noted then applied that Bayer pattern.


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ZWO claim the ASI294 is RGGB.


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Yes, RGGB is correct.  But in Nebulosity you don't get a menu which says that.

See recent similar query and answer here:

The magic X/Y pair to use for this camera is 1/1.



Edit:  The 'sickly blue' that shows initially after debayering can be fixed by selecting the Adjust Color Background (Offset) menu item, which aligns the histograms.

Edited by AKB
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Not ideal if you had cloud and the full moon but hey, it's looking doable. The bayer pattern is stored in the fits file along with the data but maybe your software doesn't look at it? Anyway, whatever setting you had worked so do some flat frames, lose the gradient and you should be onto a winner.


Edited by alacant

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