Using ColorPort for QTR grayscale and alt-process profiling

ColorPort
ColorPort is free utility from XRite that allows users to make and measure profiling targets with a wide variety of spectrophotometers, including the versatile 1Pro. This software and hardware combination is the modern day equivalent to yesterdays densitometer that provides much more information and functionality. I’ve been using ColorPort on a daily basis since 2005 and love it’s flexibility and versatility. If one is savvy enough to hack color patch spreadsheets and XML files, one can design beautiful targets for nearly any profiling purpose. I’ve preferred ColorPort over MeasureTool for years, but now that XRite has discontinued MeasureTool and the Mac OS will no longer launch it; color geeks everywhere are making the switch.

B&W inkjet printmakers and Quad Tone RIP (QTR) users in particular will love to hear that I’ve just made it easier than ever to ditch MeasureTool and start using ColorPort. Visit www.on-sight.com/downloads/ to download the 21 and 51 step gray ColorPort XML files that I’ve made for the i1Pro and iSis. These files can be installed at the following location:

Mac OS: [user folder]>Documents>ColorPortResources>refs>cmyk
Windows: C:\Documents and Settings\Administrator\My Documents\ColorPort_Resources\refs\cmyk\

I’ve also made my Grayscale and Alt-Process profiling targets available with patches for the i1Pro, and iSis and DTP70 patches on separate layers that can be enabled. These profiling targets have large 21 step patches that come in handy with irregular alt processes and some images to help monitor the tonal scale during testing. The values of the 21 and 51 step targets are exactly the same as those from QTR. Feel free to use these targets for non-commercial purposes.

With the XML files installed, launch ColorPort, and choose the target you wish to measure. i1Pro users should then click on the circular “i” to the right of the measurement device, choose spot or strip reading (I prefer spot measurements), calibrate your device and begin measuring the target patches.

If you click on the circular “i” to the right of the measurement status, you’ll see a nice window that shows your measurements in a variety of modes. Some will appreciate the densitometric values while others might like the spectral visualization of each patch.

Once your measurements are complete, click the “Save Data” button on the lower right. Choose “Tab Delimited” for the format, leave the conversion on XRGA, and make sure that the only checked boxes are “Lab” and “XYZ” with the Illuminant set to “D50” as pictured here. Save your measurement file.

You now have a measurement file that you can drag and drop onto the “QTR-Create-ICC” script to make an ICC Color Profile for your grayscale printing process! Of course, QTR users can also drag and drop this measurement file onto “QTR-Linearize-data” and use the linearization curve in QTR. Tip of the hat to Roy Harrington for his brilliant work on this script which is available for download at www.quadtonerip.com. Roy’s grayscale profiles can be used for soft proofing in Photoshop complete with hue and paper color simulation.

You can also use this profiling process to color manage Advanced B&W printing modes and alt-process negatives. More on this in another article soon.

If you choose to open up this measurement file in a text editor, the leftmost column of numbers contain the pertinent Luminosity channel numbers. If any of these numbers aren’t sequential QTR-Create-ICC won’t make a profile. If this occurs you probably have an anomaly in one of your measurements that you can manually fix in the text editor. I sometimes find a single patch in the shadows that is slightly out of sequential order, and adjusting this value so that QTR-Create-ICC can make a profile has no detrimental effects.

Measurement file with anomaly
Measurement file with non-sequential value that should be corrected to 7.71

Of course, my clients that would rather not invest in a spectrophotometer and all this geek stuff can utilize my private remote profiling service. While I think most will want to do this themselves, it’s always good to have options. I hope this is useful – enjoy making grayscale profiles!

– Scott Martin

Update 4-26-12 XRite has upgraded ColorPort to version 2.0.5 to address some issues some users were experiencing and to support the new i1Pro2 device.

13 Responses to “Using ColorPort for QTR grayscale and alt-process profiling”

  1. David Cary Says:

    Thanks for that. I have been building QTR profiles using Argyll CMS and an i1 so am interested in this. I have a question though. QTR Create ICC can make a monochrome profile but it will be positive, to be useful for making digital negatives (rather than soft proofing) the profile must be applied to a negative image. Is there an easy way to convert a curve from positive to negative. I am using the PDN curve calculator with normalised L* which may not be an ideal way of making a curve as it may not take into account print Dmax and the Yule-Nielsen effect, or something along those lines anyway.

  2. Scott Martin Says:

    I have an article coming out that will address making negatives for all kinds of alt-processes. To make a long story short – yes you can do it, and yes, using a spectro is super fact and easy and accurate in comparison to any curve method. Use the “Negative” and “Emulsion Side Down” checkboxes in Photoshop’s “Output” section of the print dialog box. More (much more) on this soon.

  3. Luca Says:

    Hi Scott,
    which target / file should I print if I’m using ColorMunki? Does Colorport work with this spectrophotomer as well?

  4. Scott Martin Says:

    As a consumer device, the Munki isn’t supported in ColorPort. However, check out this article about using the Munki for this purpose: http://bit.ly/aXHbKE

  5. David Cary Says:

    Thanks.

    David

  6. Kees Brandenburg Says:

    It looks like Colorport 2.0.3 is not supported with Lion (MacOS 10.7.3). The installer won’t install it on my startup disk and when installed on an other disk the app crashes at launch.

  7. Kees Brandenburg Says:

    update: contacted xrite and they provided a workaround for what apparently is an installer bug in colorport 2.0.3:

    “There is a bug in the Mac installer of the ColorPort software we are working on. To go around this, please right click on the installer package and go to “Show Package Content”. You can install the software out of the package content then.”

    Now I have a working copy.

  8. Scott Martin Says:

    You beat me to it. Yep, I’ve reported a number of small bugs to them – hopefully they will have an update soon.

  9. Scott Martin Says:

    FWIW, XRite has upgraded ColorPort to 2.0.5 to address some of the issues previously discussed and to support the new i1Pro2 device. Get it here:

    http://www.xrite.com/product_overview.aspx?ID=719&Action=support&SoftwareID=1168

    Scott Martin
    http://www.on-sight.com

  10. Ed Davis Says:

    Now that ColorPort 2.0.5 has been released do you have some updated instructions for the new software or at least have the folder address instead of:
    Mac OS: [user folder]>Documents>ColorPortResources>refs>cmyk
    As this no longer exists.

    Thanks

    ps. GREAT instructions

  11. admin Says:

    Thanks for your comment. XRite hasn’t changed the location of these folders in nearly a decade. I installed CP 2.0.5 when it came out and I’ve still got those folders and the files are working great there. Go ahead and make these folders if you’re not seeing them.

  12. Doug Taylor Says:

    Hi Scott,
    I used your 21 step target, color port, and the i1Pro and was able to linearize a qtr curve.
    A friend has a Color Munki. Can he use that to read your 21 step file?
    Thanks, Doug

  13. Scott Martin Says:

    Sorry, the Munki is a budget device that’s outside of the i1 family and therefore can’t be used with any software except ColorMunki. Snag a used i1Pro if you can – lots of them out there!

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