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Color Management: The Guru List

(April 2010) posted on Tue May 04, 2010

More than 20 tips and tricks on wide-format color management from seasoned experts


16. Monitor/Display Screen Setup
Accurately set up your screen to internationally accepted standards:
• White Point should be targeted to visually match your print viewing environment by iteration. Note that, even with D50 viewing, we normally find that targeting D65 matches better than D50, as a starting point.
• Black level: If you have this option, start at Minimum, Neutral.
• Tonal Gradation: L*(star), or, if that’s not available, Gamma 2.2 (yes, even on a Mac).
• Avoid cheap calibration solutions and visual processes.
• Verification: Note that comparison of your screen image to a printed “Verification Image” (e.g.—a certified proof of a good test image) can be a very useful aid to deciding on your final targets for calibration, i.e.—white point (color temperature) and white luminance. It is a great confidence boost to know for sure that your screen can match the accurate proof print. “Verification Image” is our name for a quality print known to be a true rendition of the file’s content.
—Neil Barstow, colourmanagement.net

17 Calculate Your Own Delta e
It is actually easy to create a spreadsheet to calculate delta e CIE L*a*b*: Measure two colors. Write down your L, A, and B values. You now have L1, L2, A1, A2, B1, and B2. The formula is as follows: √ [(L1-L2)2 + (A1-A2)2 + (B1-B2)2]. In Excel, square root is denoted by SQRT, and squared is ^2.
—Stephan Marsico, Digital Color Concepts

18. Use Bigger Patch Charts
If you have achieved exemplary color calibration (linearization) and ideal ink limiting, then consider creating a new ICC profile with 3000+ color patches instead of the standard IT8/7.4 or IT8/7.3. An ICC profile from 3000+ color samples provides improved color accuracy from the increased data sampling. 3000+ patch ICC profiles do not work well with output that has improper ink limits and/or a visible color bias.
—Dan Reid, RPimaging


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