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  • 1.  Kodak approval with G7

    Posted 02-23-2017 07:52 AM
    Hi 

    Any one has done Kodak Approval using G7 methodology ?


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    Suresh Vaidya
    IPP Services Training and Research Pvt Ltd (Idealliance India)
    Noida 201301
    +91-120-2540258
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  • 2.  RE: Kodak approval with G7

    Posted 02-24-2017 08:33 AM
    Hi Suresh,

    Yes, I did several Approvals in the early to mid 2000s.  In factmy experienceswith Approval actually influencedthedevelopment of the P2P target, Curve software, and the Idealliance G7 Master program (see below).
    In those early days, all my Approval clients struggled with a loss oftonalitybetween 0 and 5%, which killed delicate highlight detail in chrome reflections, jewelry, cosmetic ads, etc.
    It turned out that the official Kodak calibration method for Approval (at least back then) only held a dot down to about 3%, with nothing printing in lighter tones, yet the final result always passed an IT8 test.

    The first time I calibrated an Approval, G7 didn't exist as such, so I used an early version of the P2P target with an Excel spreadsheet to linearize the Approval down toabout 1/2%.  Then I built an ICC profile on top of those curves.  The combination completely solved the highlight problem and produced anexcellentcolor match, but the next time a Kodak engineer came in, he/she would try and replace my calibration curves with their "official" ones, resulting in lost detail again!

    The trick to restoring lost highlight detail (on Approval or anything similar) is to print a full P2P51 target and create RIP control pointsat2, 4, 6 and 8%, as well as any other points the device might need.  If you don't include those very light control points, youwon't be able to restorelost highlight detail.

    As a result of this experience, Steve Upton and I have made sure all versions of the Curve software can precisely calibrate in very fine highlight tones, right down to paper level.  It's also why Idealliance included2, 4, 6 and 8% dots in the official G7 Grayscale verification metrics, which in turn is one of the reasons for G7's popularity and success.  Previously, most color verification systems tended to ignore the 0 to 5% region, which as you know can be crucial to the success or failure of many high quality printing jobs.

    So the first thing to do when calibrating Approval (or any device) toG7 is make sure the RIPletsyou install finely-detailed curves with control points in the 2-5% range.  If it won't, you may not be able to achievethe best G7 calibration.

    Does this help?,

    Don

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    Don Hutcheson
    HutchColor, LLC
    Washington NJ
    908-500-0341
    don@...
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