Neat Image Calibration Images for Canon Rebel XT.

Discussion in 'Canon' started by ranjit, Dec 25, 2005.

  1. ranjit

    ranjit Guest

    Hi guys,

    I am trying to shoot the calibration target image from the Neat image
    software to make a noise profile from RAW. The one available there
    works for adobe camera raw, but I use capture one. I saw some one by
    name of Alan Bremner who made that profile which has 93% to 96%
    quality. The ones which I make are not crossing 74% at all Sad

    I found some posts in this forum with the person with same name so I am
    hoping it is the same person and he can help or if there is some one
    else here who has done calibration image shots on canon rebel xt, can
    you please explain how you went about it or even better if you can send
    the RAW images taken so that I can convert and make the right profile,
    i would greatly appreciate it.

    Thanks,
    Ranjit
     
    ranjit, Dec 25, 2005
    #1
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  2. ranjit

    Alan Bremner Guest

    Hi,

    I printed the calibration target onto thin card and photographed that
    at the various combinations of ISO/shutter speed that I required. I
    taped or pinned the target to a wall and used a tripod to ensure some
    consistency, and took care to make sure that the target was slightly
    out of focus as recommended. The latter isn't easy at small apertures
    so I shot quite a few images indoors by available light in order to
    restrict DoF.
    I found that using the manual fine-tuning adjustments gave better
    results than the auto-calibration. The latter method often resulted in
    75-85% quality whereas a spot of fine-tuning often increased this
    significantly.
    I hope the above helps. The most important thing appears to be the
    defocusing to prevent paper texture confusing the calibration process.
    I wish I could! Unfortunately I lost them a few weeks ago in a hard
    disk crash and because they weren't 'proper' photographs I had never
    included them in my backup regime.... :-(

    Al
     
    Alan Bremner, Dec 27, 2005
    #2
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  3. ranjit

    ranjit Guest

    Thanks Alan,

    Let me give it a shot again. Hopefully this time I might get good
    results. I didnt get what you meant by "A spot of fine-tuning". Did you
    do anything special than selecting the region on the image manually ? I
    mean did you use any of the bars on the right hand side ?

    Thanks,
    Ranjit
     
    ranjit, Dec 28, 2005
    #3
  4. ranjit

    Alan Bremner Guest

    I used 'Auto Profile with Calibration Target' initially, and if I
    wasn't satisfied with the resulting profile quality used the 'Fine
    Tuning Analyzer. To do this I looked for noise frequency sliders that
    showed yellow (or red), tried to find an area on the target that
    corresponded to at least one of the RGB values for that frequency, and
    then used 'Auto Fine Tune'. If I couldn't achieve "green" for all
    frequencies I then used 'Auto Complete' to make a best-guess
    extrapolation of the data before saving the profile with a meaningful
    name ( see
    http://www.neatimage.com/ug5/E-Devi...ng-profile-set-for-different-device-modes.htm
    for an excellent guide to organising the profile set).

    I hope this makes the process a bit clearer.

    Al
     
    Alan Bremner, Dec 28, 2005
    #4
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