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Thread: That Sunflower Image - ColorThink 2.3 to the Rescue

  1. #1
    xpatUSA's Avatar
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    Feb 2012
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    That Sunflower Image - ColorThink 2.3 to the Rescue

    Last year in July, I took a snap of a sunflower with my SD10. I had been accustomed to opening the Sigma X3F raw files in ACR 5.4, thence to PSE6 for processing. But this shot showed bad blotching in the sunlit petals; opening the same image in Sigma's Photo Pro did not. I posted but nobody absolutely knew the root cause of the blotching although there were some good guesses.

    Fast forward to yesterday when I acquired ColorThink V2.3 and, for the first time, was able to compare image color gamuts with known color spaces in 3D. I'll post a screen shot and then discuss it. It's a bit geeky but at least the flower is from the "Real World" and people do like to shoot flowers with their bright, saturated colors.

    That Sunflower Image - ColorThink 2.3 to the Rescue

    At left, we see the image straight out of the ACR box, sliders at zero except exposure. The blotching is visible as lighter patches of yellow. At center, we see the output from Sigma as a ProPhoto image - opened in PSE6 without color management. At right, the same ProPhoto image edited and converted to sRGB.

    The left gamut tells the tale all too clearly. For some reason, ACR sent an image to PSE heavily clipped to the sRGB color space. On the other hand, the center gamut lies well within the sRGB color space because the image was created in the ProPhoto space - hence it's paler appearance when opened un-managed in PSE. The center gamut shows quite clearly that there is headroom within the sRGB space, enough to edit the image, in terms of both hue and saturation, sufficiently to come up with an un-blotched image.

    The point of this post is that geeky stuff like color gamuts and representations thereof can be helpful with 'difficult' images and avoid a lot of guesswork and waste of paper for people who print. The proof of the pudding is in the right-hand image's blotch-free appearance and the nice curvy occupation within the sRGB gamut.

    The image itself is an un-processed low-res snapshot and is not really offered for comments as far as quality is concerned . . .

  2. #2
    davidedric's Avatar
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    Jul 2012
    Cheshire, England
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    Re: That Sunflower Image - ColorThink 2.3 to the Rescue

    Hi Ted,

    I am a bit of a geek, and I love the idea of visualising 3d colour spaces (my university subjects taught me to think in 3d/4d) but at $149 I can't justify it to myself. Thanks for posting though, it really makes the point clear.


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