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Lots of spots

Keith Townsend
in PixInsight
Hi
Can anyone suggest a cure for this issue please. I suspect the spots come from processing somewhere.
The images were taken with an Altair 269c and can be found in most of my images.TGV will not remove them and they spoil just about every final image of mine at the moment (if I zoom in).
My routine in PI is to calibrate using cosmetic correction (both hot & cold pixels) with both thresholds set low - hot maybe 1.5 and cold 0.7.
Could it be related to the hot pixel removal?
I then tend to do PCC, DBE, Stretch and then ATW n/r before curves and colour adjustments etc.
Any suggestions gratefully received.
The attached are at various stages of processing.
Thanks
Keith

Comments

  • BlockHeadBlockHead
    I think you are asking why don't you get a completely smooth result? ATW, MLT, TGVDenoise all work on layer/scale sizes that will always look like this. 

    In my tutorials, I demonstrate one way to get a different result (and attack things less with the noise reduction) is to first prep things my REMOVING the first (and maybe second) layers entirely with MLT. Then try your noise reduction algorithm of choice (TGVDenoise is best)... you will find much better results. 

    -the Blockhead
  • Roger Smith
    Keith,
    I also use a color CMOS camera. I greatly reduced my problems with small black spots visible in nebula when I learned (from Adam) to do CC as part of WBPP 2.0. This cancels any hot pixel leftovers before debayering. A debayered hot pixel is difficult to eliminate. So they can become bigger problems after debayering and integration if not removed first. 
    He points this out regularly in his tutorials whenever he is doing WBPP. 

    I also do the MLT before TGVDenoise as per Adam's tutorial to reduce larger black spots in the dark sky background that can show up if you do not do MLT.
    Roger
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