Resolved calibration ha images

Discussion in 'Image Processing' started by shane, Jan 3, 2019.

  1. shane

    shane Standard User

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    HI all I have a problem when calibrating my HA oiii sulf images they all turn out way to dark and unuseable is there a way of fixing this its only started since upgrading to maxlm dl6...my RGB images I have no problems with calibration Autosave Image -0008ha.jpg
     
  2. Doug

    Doug Staff Member

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    We can't tell anything from JPEG images. You'll need to upload FITS.
     
  3. shane

    shane Standard User

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    ok here is a compressed fits
     

    Attached Files:

  4. Colin Haig

    Colin Haig Staff Member

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    I just had a fast look - not much in there. I see you posted the same file twice.
    Can you post the original unprocessed light Ha FITS, and then your dark and bias?

    Tell us a bit about your setup - eg Which camera is this? QHY163? Mono or color?
    Filters?
    Telescope details, any focal reducer, light pollution filter, etc.
    What were the sky conditions like at the time? eg any humidity or thin cloud?

    A few suggestions while you're at it - when you have a spare minute,
    Enter the optical parameters of the telescope and site into File... Settings... Site and Optics.
    Then this will show up in the FITS header for calculations and cross-checking results.
     
  5. Doug

    Doug Staff Member

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    Something is wrong with your bias and/or dark frame. The average level is different from the light frame, with the result that the image was basically subtracted to below zero and disappeared.

    Make sure you are using the same imaging mode settings for your calibration frames and light frames. I'm not sure what options are available on your camera but they should have the same Readout Mode etc.

    Also make sure you have an appropriate value in Set Calibration / Advanced - Pedestal. It should be at least 100, and may need to be larger on some cameras.

    https://diffractionlimited.com/help/maximdl/HID_PROC_SETCALIB.htm
     
  6. shane

    shane Standard User

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    All sorted I think looks like it works better on median not average in combined type
     

    Attached Files:

  7. shane

    shane Standard User

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    thanks for your help I will add the details too my telescope setting cheers
     
  8. shane

    shane Standard User

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    thanks for your help...IM not very good at explaining things no the computer.. I have sorted my calibration problems cheers thanks :)
     

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