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Comet not subtracting

Arthur Trail
in PixInsight
Hello,

 I am very new to Pixinsight (and AP) so please excuse the ignorance. I am following the Comet Academy video, "Traditional Comet - no SXT". I have made it to the Comet Subtracting process and I am having no luck at all with extracting the comet data from any of my data sets (LRGB). I have repeated the process about 4 times while watching the video, and cannot figure out what I am doing wrong. Are there any common "gotchas" that someone can share with me?

Thanks!

Art

Comments

  • BlockHeadBlockHead
    Yes there are (watching the more recent videos will help).
    I explain that for many comets that are not bright you will want to subtract WITHOUT using LinearFit.
    It is the LinearFit that is the issue. 

    The Traditional Method is an old one I made before Comet Academy... not really recommended..but I include it for completeness.
    I need to make the guide for it (which would have spelled this out just as I have on all of the others).

    Please confirm that unchecking Linear Fit helps.
    It will not be a perfect subtraction (leaving some residuals). But the residual can be rejected and later cleaned (as I show in other recent videos). 

    I would suggest you watch the Standard Comet (first example). Even though you are not using SXT...everything else is the same.

    -the Blockhead

  • Arthur Trail
    Will do! Thanks!
  • Arthur Trail
    So, would you recommend that I just bite the bullet and buy SXT? Will this be what I will primarily be using with DS objects anyway?

  • BlockHeadBlockHead
    Yes. It is truly part of today's workflow in terms of handling many aspects of stars versus non-stellar content in images.
    -the Blockhead

  • Arthur Trail
    OK. I will get it. Hopefully it will run on my older Mac.
    I did try to uncheck "Linear Fit". It subtracted everything.
  • BlockHeadBlockHead
    Yes. It is truly part of today's workflow in terms of handling many aspects of stars versus non-stellar content in images.
    -the Blockhead

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