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Thread: Grainy/Mottled output with Profile in CPS

  1. #1
    Join Date
    Aug 2017
    Posts
    3

    Default Grainy/Mottled output with Profile in CPS

    We recently purchased a Ricoh 7100 and are also new users to CPS. We are currently on version 4.9.4.26. When we run any stock profile that come with the press we get a nice smooth output but when we use any G7 profile(made using CPS) we are getting a grainy appearance in the output. We have tried multiple combinations of settings within the profile and within the Ricoh job properties. We have even been to the Ricoh Demo center local to us and got the same output on their presses as well.

    Kyle

  2. #2
    Join Date
    Apr 2010
    Location
    Foster City, CA
    Posts
    283

    Default RE: Grainy/Mottled output with Profile in CPS

    Hi Kyle.

    As we discovered yesterday two problems contributed to this. First. in CPS 4.9.4.26 the calibration set you made was not being applied when printing the profiling patches. There is a sticky at the top of this forum that I will update today stating this was a known problem with G7 calibration in 4.9.4.26 but as we saw the problem happened without the G7 also.

    Today CPS 4.9.4.28 is live for download here <http://www.efi.com/marketing/fiery-servers-and-software/downloads/fiery-cps/>. This fixes the problem so no need for workarounds and you can also safely include G7 calibration as part of the creation of the calibration set.

    The other problem and more likely the cause of the grainy issue was the black generation used to create the output profile. Because you profile with CPS the simple way to solve this is to use the full printer profiler and when you get to the separation settings window select a factory profile from Fiery at the top to get its settings. Pick the profile for the paper most like the one you are profiling, Coated Matte in this case. Now you get the factory black generation that we custom tuned to look the best which the press manufacturer approved (in this case the smoothest and least grainy).

    One side note that we also learned when reviewing this is that you had spent time trying all the different halftone screens trying to find the smoothest one to solve the problem. This happens to a lot of users who are running into a custom output profile with the wrong black generation.

    The way to find out the best halftone setting is to look up your Fiery on the IDEAlliance digital press certification listing.

    That listing is here: <https://www.idealliance.org/certification/digital-press-certification/certified-digital-electrophotographic-press-systems>

    Your Fiery's ADS is here: <http://connect.idealliance.org/HigherLogic/System/DownloadDocumentFile.ashx?DocumentFileKey=f5df8632-dc75-741e-b6d0-12c9542adb76&forceDialog=0>

    As we see in the ADS, the "200 dot + fine text" screen is the best choice that gives lowest M score (least mottling and banding) which is why we used if for the certification. I know you already are aware of this but I wanted to share it with all the other forum users that might be fighting grainy output. Use the screen from the ADS, use CPS with the correct loading of profile settings from a factory profile, and grain issues should be resolved.

    The last note is that while our max GCR will give you better grays (and saves more toner than any other profiling tool on the market in tests we did with Ricoh) it will also can introduce grain. So if you want to experiment with it, still start with importing settings from the factory profile, then enable max GCR, then go to Edit Black and change the start to 25-30. If you see too much contrast with max GCR then try setting black generation to 90 or even 80. You might also reduce the black width to 40-50 if the grain is showing in colors not just in neutral grays.

    ~Lou

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