Results 1 to 7 of 7

Thread: PROFILING: Multiple Lighting, which is Correct?

  1. #1
    StarDigital is offline Fiery Forum Expert Contributor StarDigital is on a distinguished path
    Join Date
    Mar 2015
    Posts
    461

    Default PROFILING: Multiple Lighting, which is Correct?

    When i was building a new color calibration ( i was going for 300 dot ), i found a large number of different lighting settings for the calibration. It took me quite awhile and a lot of trial and error before i found the one that printed a pantone list closest to my pantone book. And it was listed different from the lighting i have in my print shop. My question is:

    1. What are they
    2. How do they work
    3. How can i choose the right one for my printer.
    4. Are current calibration profiles adjustable to new lighting sets.

    As i have already created my 300dot profile for my xerox 1000, so i only need the 4th answered for me. But i would like, for everyone else sake, the others answered as well.

    Dan

  2. #2
    Join Date
    Apr 2010
    Location
    Foster City, CA
    Posts
    287

    Default RE: PROFILING: Multiple Lighting, which is Correct?

    Good question.

    The idea is that you make a profile for the lighting conditions you will view prints in. What setting worked the best?

    Are you viewing the prints in a D50 booth? If so we would think that would be the best setting but to be honest we don;t have all the illuminant conditions shown in the software to test. We tes† with D50 since that is the standard, the idea is that chromatic adaptation will work for the other illuminants. The way this works is that when spectral measurements are converted to tristimulus (LAB or XYZ) values for profiling, the formuia for that conversion is based on the iliuminant. So we can use something other than D50 and appearance should be better in that lighting.

    We'd love to have feedback on what setting worked best and what lighting conditions you are viewing in. I'd al;so like to know which Pantones you tested and confirm you have a current Pantone Solid fanbook. Pantone puts out a number of books like Process (which won't match) and Bridge (half of which will match). I'l lshare some info about that in my next reply.

    Thanks.

    ~Lou

  3. #3
    StarDigital is offline Fiery Forum Expert Contributor StarDigital is on a distinguished path
    Join Date
    Mar 2015
    Posts
    461

    Default

    When i did my profiling for 300 dot i started with the lighting i had used for 200 dot, but they didn't work. I think this was the main cause of my post about 186 C getting cyan in the color. As the default had Cyan. I decided to be a bit more thorough this time around. I thought that since my shop has the pure daylight white bulbs (gotten for best color matching abilities) that the profiler would use that. Unfortunately the profiler had 4 daylight settings and none of them produced pantones to match the PANTONE books i have. My process is this

    1. choose a lighting setting, create a profile. (don't exit program)
    2. apply that profile in the spot color settings (saved a preset for quick repitition)
    3. printed out (8x8) of certain colors that i use often, blues reds, yellow, oranges browns, a few purples, ranging light mid tone and dark, across the book so that i have 1 sheet printed with color squares. Then i use the swatch book to see how close i got. I used coated colors on a coated stock to get best results. I go for the solid side on the swatch book not the process side, even though many of them are too brilliant for the printer to match, these i just see if they 'look' decent to my eye. Before all that i check to make sure the 186 C had no cyan in it, if it did i got the wrong lighting.
    4. Back up to the lighting settings again to choose a different one (renaming involved, best to use temp, until the right one is found then name that properly), repeat.

    Turned out the lighting for me was the mid morning mid after noon light D55 and not the daylight ones: B C D65 or GTI Daylight. Also there was a graph on the right [view] and it used XYZ coords. I could make a custom color from that but i have no idea what i would be doing.

    As for the d50 boot we use to have one but it competed and failed with the shop lighting (real headache matching with multiple lightings). So we just turned the shop lights to the best possible, and used them.

    I have a PANTONE bridge both coated and uncoated and one used for offset ink mixing that i use for matching our offset side.

    Questions: the XYZ coord looked like a version of the LAB 3d model, and if the lighting isn't correct you'll get 'dulling' colors in your pure sets. Like 186 C and 100 C for example. Neither of which should have CYAN. So how is choosing d50 correct, if when you print it out and see it in multiple different lights it is 'impure'. is the d50 'booth' a full spectrum lighting that accounts for all lighting's?
    I understand that seeing a print in the dusk dawn time will look different than in the noon day sun, even cloudy times or flourescent interiors. but the colors should remain pure. Perhaps your deviation algorithm may need looking at. It shouldn't be an even shift across the board.

    Any questions i'd be glad to answer and help anyone out.

    Dan
    Star Digital Print
    Lincoln, Ne

  4. #4
    Join Date
    May 2015
    Posts
    6

    Default

    Dan - thanks for the helpful outline of what you guys do. We're just getting into the nitty gritty of profiling all of our stocks with CPS and are also finding that testing our spot colors against Pantone swatches has proved to be the most accurate overall way to reproduce colors - We ALSO have found the best luck with the Mid Morning light profile as opposed to the D50 profile (which we use in our light booth) however it seems that we can never get the grays to line up, they usually tend to skew warm. We're happy with the other colors and don't want to adjust the curves if we don't have to.. Is there any way to fine tune the gray balance? On an EFI help page it mentions using the autogray option to help, however it requires a flatbed glass scanner which we don't have for the Konica c1100 - Dan or Lou, is there anything you recommend to help with fine tuning the profile? Is there something already in Color Profile Suite that I might have missed?

  5. #5
    StarDigital is offline Fiery Forum Expert Contributor StarDigital is on a distinguished path
    Join Date
    Mar 2015
    Posts
    461

    Default

    Hi acookster101,

    Glad i could help. For your grey balance (full CMYK grey??) all i can suggest is to play with the XYZ lab custom lighting that it gives you and also adjusting the Black level settings. As i was going through my own experimentation i set the final values from top to bottom:
    260, 100, 5, 80, 50, 65, 40, 100, GCR No, Optim No, D55 Mid Morn

    Apart from that i don't know if i can help, as i am pretty novice at the CPS settings.

    Dan

  6. #6
    adam1991 is offline Fiery Forum Expert Contributor adam1991 has proven very helpful adam1991 has proven very helpful adam1991 has proven very helpful adam1991 has proven very helpful adam1991 has proven very helpful
    Join Date
    Feb 2010
    Posts
    1,029

    Default

    It's not CPS that makes the grays skew warm. It's the default Fiery color settings.

    Let CPS 4.6/4.7 do its thing, then turn all the gray settings in expert mode to OFF when reprinting your target print.

    Still not as good as I'd like it, but the warmness goes away. At least, on my well-balanced C1100 and C1060.

  7. #7
    Join Date
    Apr 2010
    Location
    Foster City, CA
    Posts
    287

    Default RE: PROFILING: Multiple Lighting, which is Correct?

    Are you using the max GCR setting in CPS profiling? If you are using Express Profiler you'll need to be at CPS version 4.7 to see it in the prefs. If you are using Printer Profiler then set Max GCR and Optimize colorimetric precision in the profile settings. Does that help? What other black setttings are you using?

    ~Lou

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts