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Problems with photometric colour calibration

Keith Townsend
in PixInsight
Hi - I am unable to plate solve an image I have with reasonably good data, taken with a OSC Altair camera.
I have integrated 40 x 240s images of NGC6992 (Easter Veil Nebula) which is an extremely star studded section of the sky and ppc consistently fails to plate solve.
The fits header states the correct coordinates for the centre of the image and the focal length is also correct (as far as I can tell. Taken with a 102mm refractor and a .79mm reducer/flattener.
I get the following error message:

*** Error: Unable to find an initial set of putative star pair matches.

*** Error: The image could not be aligned with the reference star field.

Please check the following items:

  • The initial coordinates should be inside the image.

  • The initial resolution should be within a factor of 2 from the correct value.

  • Adjust the star detection sensitivity parameter, so that the script can detect most of the stars in the image without mistaking noise for stars.

  • The catalog should be matched to the image. Choose the appropriate catalog and magnitude filter, so that the number of stars extracted from the catalog can be similar to the number of stars detected in the image.

*** Error: Unable to plate solve image: Alignment failed.

This usually happens because the initial parameters are too far from the actual metadata of the image.


** Warning: Process finished with errors:

PCC_T_D6KGG9NXVL49.xisf: The image could not be plate solved

 

I have no idea what adjustments to make to try to get this working!
Any suggestions welcomed.
Thanks in advance
Keith

Comments

  • BlockHeadBlockHead
    Do you have a preview associated with the image?
    You will need to show some screenshots of the settings and zoomed in region of the image ..perhaps at 400% - 600% .
    -the Blockhead
  • Keith Townsend
    Thanks - hopefully this is what you need?
    Keith
    NGC6992_screenshot.JPG
    1920 x 1039 - 236K
  • BlockHeadBlockHead
    Remove the preview from the image.
    Do you have the GAIA catalogs installed physically on your machine?

    -the Blockhead
  • Keith Townsend
    No I don't have GAIA physically on my laptop....
    I removed the preview and ran pcc again - same result. Nada!
  • BlockHeadBlockHead
    If you choose to install those on your machine... we will both have the same situation, I would be happy to investigate further. 

    (You should also try to ignore existing metadata, it is an option you can check... if you have disparate info in the header..and that is taking precendence...you will have exactly the problem you are reporting)


    -the Blockhead
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