Problem Cleaning Up Dark Columns

[SeattleStarGazer]

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

[aworonow]

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

[SeattleStarGazer]

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?

[jkmorse]

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