[gregbradley]

Originally Posted by multiweb

Hi Greg, are you using an OSC or mono? Process is a little different.

To make a bad pixel map in CCD Stack, load one sub, a 20min or longer exposure dark frame. Open the bad pixel map dialogue box, click on create map, then go to the reject range algo in the rejection standard drop down menu. Select a range to reject until you paint all the hot pixels and your column as well. When you're happy with the map, enter a name and save it. I usually use the name of the camera and a timestamp like <camera>_20160514 . To apply the map, load your sub then apply it. Tick the box to set the painted pixel to 0. Next step is to interpolate those pixels as they're all black in your sub. Then you're done. You might want to redo your map every 6 months or so, like your dark library. PixInsight has a cosmetic correction process that will do the same.

Thanks Marc. I will try your process. I did do most of those steps but not the check box to set the painted pixel to 0 so I got some dark rectangles where the correction took out too much.

Rick went over the cosmetic correction tool in PI so I may also try that if no luck with CCDstack.

Did you find you had to do a 20minute dark for it to work?

Originally Posted by Shiraz

have a look at https://pixinsight.com/forum/index.php?topic=2869.0

I used to use Sander's software to clean up column issues with my QHY8 - from memory it worked well. Haven't used the PI script.

I'll look that up. Is that the cosmetic correction script for PI?

Originally Posted by glend

Seems too complicated in PI to me. My mono Canon has a bad pixel column, a bad row, and a bad hot pixel and DSS cleans it up perfectly. You need flats that show the bad column, and darks that show the hot pixel area, and other than that its just ticking the cosmetic cleaning you want DSS to do. It finds bad columns and rows automatically and replaces the bad pixel with an average of the ones on either side. If you dither between exposures it gets even easier. Anyone with sensor flaws should be dithering imho.

Thanks for the tip.

Originally Posted by DJT

+1 for using Pi. Takes a couple of mouse clicks then integrate with batch processing and you can save then reuse the process settings for future images.

Where's the emoticon for fan boy?

Originally Posted by DavidTrap

PI cosmetic correction. You know you want to make the change Greg ;-)

Yes I already went to one of Rick's tutorials. I tried once since and no luck but I am sure I can get it to work. One issue was the lack of feedback on applying calibration. With CCDstack you see the result immediately.

DT

Originally Posted by Peter Ward

MaximCcd has an excellent bad pixel mapping and removal routine (from memory as sub function of its image calibration menu)

You can define partial or full rows or columns, as a numeric entry or simply by using the mouse cursor, as well as define hot or cold pixel cut-off's. While my current 16803 has no bad columns, there are some hot pixels which are non-linear that it cleans up in the blink of an eye.

Thanks Peter. So far I have not used Maxim. I still use CCDsoft or Sky X.

Originally Posted by RobF

Or just dither more, as I expect you're no doubt fully aware of for DSOs. Perhaps not so helpful for widefield/landscape of course.

Yes dithering is probably what changed. Although I found the lines vanished with regular darks. These were longer exposures and the darks don't match exactly for length.

Originally Posted by Eden

Hi Greg,

If you don't mind me asking -- which camera is this? Is it a whole column defect or just partial?

ST8300.

Greg.