Basic Guide to Color Calibration using a CMS (updated and enhanced) - Page 61

My only beef with dE is that it only tells you the magnitude of the error and not the direction of the error(s).

Say you have two points (to keep it simple: 10% and 20% on your greyscale.)

Say both have a dE of 2.5, but the 10% point is +Blue while the 20% point is +Red ... now you have an effective relative dE of 5.0 ...

Now imagine the chaos that could happen when you rely on multiple dE calculations around the gamut to figure out if you have your CMS setup "right."

dE is used in combination with actual measurements of RGB relative levels for grayscale

Yes ... but it's very easy to get caught up in chasing the dE's while neglecting to watch the relative shifts. IOW your "D65" @ 20% might not be the same "D65" you have @ 80%. And it gets crazier once you dive down CMS rabbit hole, especially as the calibration session drags on and fatigue sets in.

that's why adjustments are made while looking at the actual data and dE is used afterwards to tell you when you're done... dE on its own doesn't tell the whole story but if you use a good formula it will complement looking at the actual grayscale or gamut data/charts/graphs

However, I'd say if you can get grayscale flat across the entire range and within a couple percent of the 100% target line, you wouldn't need to worry about such things at all. Most sets can get close enough to an ideal, flat grayscale that what you mention becomes a non-issue.

Do this work in the ChromaPure Gamma module. It's all there on one page: gamma, GS balance, and dE.

What are the cons of using a meter in contact, versus non-contact, on a plasma? I am thinking specifically of using an EyeOne Display 3.

Tom says "NO" to contact/plasma!


bob

I'm getting that impression, but haven't found his comments on why yet.

Plasmas put out a lot of heat which will affect the life of a meter in contact as well as influence readings as it heats up.

Thanks. I wasn't sure if that was the case with the EyeOne Display 3. Is there some rule of thumb for how far I should place the meter from the display?