Author Topic: Problem Cleaning Up Dark Columns  (Read 969 times)

Offline SeattleStarGazer

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Problem Cleaning Up Dark Columns
« on: 2016 December 09 19:21:22 »
I have a group of O-III exposures with a dark column about 4-5 pixels wide running about 2/3 the height of the sensor. It's not completely dark, but kind of salt and pepper mixed in with dark areas. Using CosmeticCorrection, I did a defect map and have played with the cold pixel SD but the column doesn't go away it just seems to get smoother. Any suggestions?

Wayne

Offline aworonow

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Re: Problem Cleaning Up Dark Columns
« Reply #1 on: 2016 December 10 13:55:26 »
If the "smoothness" is the distraction, use Pixel Math to add some noise to the columns. Experiment with the standard deviation of Gaussian noise, for example.

AlexW

Offline SeattleStarGazer

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Re: Problem Cleaning Up Dark Columns
« Reply #2 on: 2016 December 13 21:21:21 »
Thanks! I'm not an expert in PixelMath yet, Just using it to combine NB images,  so is there a way to limit the application of the process to specific columns or column ranges?

Offline jkmorse

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Re: Problem Cleaning Up Dark Columns
« Reply #3 on: 2016 December 14 08:32:53 »
Wayne,

Try using the CanonBandingCorrection script.  It is not just for Canon cameras but works on any horizontal band in your image.  You may need to play with the settings a bit to get the right effect but it works really well for what you are seeing if we are talking about your image of the Horsehead region.

Jim
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