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Author Topic: High Delta E after monitor calibration  (Read 9948 times)

Jack Hogan

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Re: High Delta E after monitor calibration
« Reply #20 on: January 06, 2018, 12:23:37 pm »

Ya, but the "JND" is supposed to be a dE of 1.0 in LAB scale.

It seems that more recently folks have been using 1 dE2000 as a JND.  dE2000 is in general less sensitive than plain old dE(76) - that is it takes more dE's to make 1 dE2000.

Jack
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digitaldog

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Re: High Delta E after monitor calibration
« Reply #21 on: January 06, 2018, 12:49:21 pm »

The formula is important! I prefer dE2000 because in most cases, I'm interested in small(er) differences (distances) between two sets of colors. And it's important to consider where the colors are in overall color space (neutrals vs. saturated colors) and if the number provided is one dE calculation or an average of more than one. The report is kind of important and few reports are better than what we can get in ColorThink Pro and BabelColor (the later is great visually):



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Doug Gray

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Re: High Delta E after monitor calibration
« Reply #22 on: January 06, 2018, 03:59:44 pm »

It seems that more recently folks have been using 1 dE2000 as a JND.  dE2000 is in general less sensitive than plain old dE(76) - that is it takes more dE's to make 1 dE2000.

Jack

Hi Jack,

Yes. Generally dE00 is smaller than dE76 except for the critical neutrals where dE00 can exceed dE76 by as much as 50% but only in the hue shift critical yellows and violets.

OTOH, outside of neutrals and very near neutrals, dE00 is almost allways a fraction of dE76. Take the two greens L*a*b*: (50,-65,0) and (50,-70,0). By inspection these have a dE76 of 5.0 but the dE00, which is perceptually better (and computationally messy), is the barely noticeable 1.25.

I explored a bit about how dE00 responds to saturation and hue here:
http://forum.luminous-landscape.com/index.php?topic=111560.0
« Last Edit: January 06, 2018, 04:18:08 pm by Doug Gray »
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The View

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Re: High Delta E after monitor calibration
« Reply #23 on: January 06, 2018, 06:36:39 pm »

This is when you start typing or just hitting the keyboard, right?

You might just have a USB connection issue if at any point you are utilizing that type of connection during and after profiling. I'm not familiar with how your display setup is but just as it has been suggested, test by hooking up another monitor (cheapo or old used one) and don't even calibrate it or hook up any device through the USB or any other connection and see if you get this increase/decrease in brightness associated with keyboard activity.

If it doesn't do the brightness fluctuation, then it may be the internal electronics of the NEC display at issue or near or at failure. If it does with the test display, then it's most likely with your internal electronics of your device connection pathway be it USB, Firewire or whatever is used during NEC connects and profiling routines.

No, I discovered that it's not connected to typing. That was a chance correlation.
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Tim Lookingbill

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Re: High Delta E after monitor calibration
« Reply #24 on: January 06, 2018, 10:58:17 pm »

No, I discovered that it's not connected to typing. That was a chance correlation.

This is what I was referring to as well which hasn't been addressed here by other contributors...

Quote
I just did another calibration and it totally failed (even though spectraview OK'd it). I can see it the whites are too blue.

In three instances I had noticed that after a mouseclick the display got brighter...

I reduced the intensity to 130 cd/m2 and got the Delta e down to 6.71, average 3.7

I'll see how daytime editing is with this or if I can turn down the intensity even more.

It just did that thing again where the display decreased intensity in a step just like it does when profiling it...

This is highly unusual behavior between display and computer circuitry. My suggestion since it doesn't appear you're going to troubleshoot this with the spare display, is to tell this to an NEC support technician to see if they've encountered similar behavior with other NEC owners.

Since you mentioned you are making money as a photographer, time is money and the trouble you describe in this thread is so rare that troubleshooting may send you down a long rabbit hole that might wind up being total waste of time with no solution.

Or just buy you new NEC replacement. They're only around $1200.
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Garnick

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Re: High Delta E after monitor calibration
« Reply #25 on: January 10, 2018, 08:12:46 am »

That self Color Correction - is it part of Spectraview II?

I don't think you need a cleaning app on a mac - you just pull the app into the trash.

"I don't think you need a cleaning app on a mac - you just pull the app into the trash".  I realize this is not in direct reference to this thread, but a rather disturbing notion nevertheless I believe.  How often have you trashed an app by simply "Trashing" it?  When you have some spare time, check your Libraries, both Macintosh HD(apps etc) and User.  Go to preferences in each case.  I think you will find an abundance of prefs(.plist etc.) from the apps you have supposedly trashed, still residing there.  If that is the case you should definitely Trash those prefs, since they can wreak havoc when you are reinstalling an app, for whatever reason.  Simply trashing an app generally does exactly that, but it does not trash the supporting prefs etc.  There are a number of app "cleaners"(trashers) available, some of which have been mentioned previously.  For many years I've been using "App Zapper", and have never found any prefs left behind that should not be there.  Just a thought.

In reference to the main topic, I've been using PA series NEC displays for many years, along with the Spectraview calibrating & profiling software.  I originally used the Spyder hardware, but have recently opted for the i1 Display Pro.  My main working display(PA27W...) is now 5+ years old and is still clicking along as expected, with many hours of use.  I normally calibrate to a luminance of 100 cd/m2 and produce a dE of .30.  I also have the screen saver kick in after 10 minutes, and if I'm leaving the computer for a short time I initiate the screen saver manually.  I generally produce two calibrations for different situations, one at 6500K and my main working cal at 5500K, and all at Native Contrast Ratio.  On my most recent cal I also did a 5500K with a contrast ratio of 350:1.  That cal produced a dE of .14.  The NEC seems to be cruising along as expected and I'm sure I'll be able to get a few more years out of it.   

Gary

« Last Edit: January 10, 2018, 08:16:31 am by Garnick »
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Gary N.
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