My Green California Nebula

Discussion of using SharpCap for Deep Sky Imaging
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N2lk
Posts: 2
Joined: Sat Aug 01, 2020 1:30 pm

My Green California Nebula

#1

Post by N2lk »

Hello All,
I have been lurking here as I learn how to use this great Software. Now I have a green California Nebula problem. This is one single 2 min exposure, Raw16, ASI183MC-Pro and using a ZWO Dual band filter. It lets thru Ha and OIII. This is one of 70 exposures I took with flats and darks...after stacking I get a nice Green Nebula....
Bortle 4/5 skies....using a Canon Zoom lens in this case at 150mm...Sharpcap Pro via Live Stack and I saved all the single shots..then took flats and darks.

I must be missing something. Even with the filter and light pollution, I thought I could get the proper color balance.. I have been playing with this on and off for a few weeks. Ran thru Pipp first, then stack..same green
Run and stack thru Nebulosity and see if that did anything..nada...still green...

Any thoughts appreciated and clear skies all...
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admin
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Re: My Green California Nebula

#2

Post by admin »

Hi,

the first thing I would suggest is to try testing the camera and a terrestrial target to make sure that the colours come out correctly and a target that you know the colour of. At a minimum, try shining a red torch into the camera or into the telescope which should give you a red colour on the screen – if you end up with green or blue instead then you have somehow got the Bayer pattern for your raw images wrong.

You may also notice that when you try taking a terrestrial photo you also see the green colour cast (even if items that are red/green/blue are appearing roughly right). In that case the problem is likely that the cameras more sensitive in the green wavelengths than at the red and blue wavelengths, in which case you may be able to fix the colouring of the images either in postprocessing or by using the colour balance controls for the camera.

Cheers, Robin
N2lk
Posts: 2
Joined: Sat Aug 01, 2020 1:30 pm

Re: My Green California Nebula

#3

Post by N2lk »

Thank you Robin for the comments..I will look into that and have a great day.
John
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