Staff Assigned: Adam Robichaud Filters not showing in Set Calibration menu

Discussion in 'Image Processing' started by Andrew Jackling, Apr 29, 2017.

  1. Andrew Jackling

    Andrew Jackling Standard User

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    Hi all,

    I am using CCD images that were taken in 2002. I have science, biases and flat field images taken in three filters; B, R and I. I am trying to calibrate the science images using the set calibration menu. However, when I point Maxim DL 6 to my biases and flats and press "auto-generate", it does not seem to recognise the filters for the flats. Instead it just plonks the flats into one group with all of them together. I have looked at the FITS headers for the images and the "INSFILTE" does correctly show the filter for each image.

    Additionally, when I attempt to perform photometry and I try to put in the magnitude for a reference star, it does not prompt me to load the magnitudes for each of the filters.

    Thus, is there a way for me to get the filters to show in the set calibration menu? Or is it possible that my calibration is working correctly once I manually organise the groups myself?

    Any help is much appreciated.

    Andrew
     
  2. JoshuaHufford

    JoshuaHufford Cyanogen Customer

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    If the calibration files weren't taken with MaximDL, the program won't always recognize what type/filter the images are. You may have to go in and manually edit the fits header of each file, or I think if you use the calibration wizard you might be able to tell maxim what files you want to use, been a while since I've used that.
     
  3. Andrew Jackling

    Andrew Jackling Standard User

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    Hi Joshua, thank you for the speedy reply. I did try using the calibration wizard but it still clumped the flats into one group all together. I agree that it seems something in the FITS header has to be altered, but what if not the INSFILTE part?
     
  4. JoshuaHufford

    JoshuaHufford Cyanogen Customer

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    I had to do this once a long time ago, I think I took a calibration file with maxim that I needed then compared the fits header of the new file to the one I needed to alter and changed the values as needed.
     
  5. Andrew Jackling

    Andrew Jackling Standard User

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    Okay so turns out simply adding a new line to the FITS header with the keyword "FILTER" and providing the correct letter for the filter is all that was required. I did this for all the images and it has done the trick perfectly. However, I still have the issue of the photometry menu failing to prompt me to enter a reference star magnitude for the different filters.
     
  6. JoshuaHufford

    JoshuaHufford Cyanogen Customer

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    Sorry I'm not help with photometry, but I'm sure someone else will be able to help you.
     
  7. Doug

    Doug Staff Member

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    Yes we use FILTER not INSFILTE. That keyword must be used by some other program.

    I'm not sure why you're having trouble with photometry. Perhaps you could upload several images so we could try it? Just upload enough to illustrate the problem.
     
  8. Andrew Jackling

    Andrew Jackling Standard User

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    Hi Doug,

    The photometry problem I described was another FITS header issue, as each image I loaded had the object name "SA104B", "SA104R", etc. Once I renamed these to "SA104" for all, they grouped correctly in the photometry tool.

    However, I'm now having a separate photometry issue when tagging stars in my science images, which is the star cluster M67 (B,R and I filters). Once I tag over ~125 stars, the program continues to tag stars as I instruct, but fails to put a green ring around the star, so I have no way to see graphically whether I have tagged that star or not. Additionally, as soon as I press the graph tab the whole program crashes. I did find a separate thread on these forums describing exactly this issue but there did not seem to be a resolution. I'm hoping to tag >300 stars in my science images to produce a color-magnitude diagram and I don't think Maxim will be able to handle that. Maybe I should look to something else to do photometry in this case?
     
    Last edited: May 2, 2017
  9. Doug

    Doug Staff Member

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    Should be able to do it. I'll ask one of our guys to have a look.
     

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