problems with calibrating a NEC display

[Ken Bennett]

Greetings,

I have a NEC Multisync LCD2690WUXi monitor, purchased in summer 2010. I use the included puck and NEC Spectraview software to calibrate it.

I've noticed that the delta-E measurement has gotten worse with each calibration. In July 2010 it was 0.32, and it stayed below 1.0 until May, 2011, when it was 1.71. This past October it was 3.14, today it is 4.57. I also note that the Display Luminance has been decreasing each time, from dead on (240cd/m2 last summer) to 212.8 today.

I have tried the calibration with the office lights both on and off, and get similar results. Is this a normal progression for this monitor? That is, should I expect this to happen after 18 months?

The only thing I might be doing differently is performing the calibration at the end of the day rather than the beginning, so the monitor is quite warm.

Thanks for any thoughts.

Ken

[bill t.]

I've got the same model.

12,860 hours
Firmware 1.00.08
436:1
135 cm/m2 (same as requested)
Delta E Average 0.44, Maximum 0.67

I have noticed the amount of correction required needed in the red channel has gradually increased, but only very slightly.

The display gamut triangle seems slightly bigger with my new i1 Photo Pro puck than with my old i1Display2.

Have calibrated at many different times of day.  I usually drape a black t-shirt over the puck, trying not to block the monitor's vents at the top.

I think something's wrong with either your puck or maybe your backlight.

Note that if the puck is pressed hard against the monitor face or if the screen is puckered from the suction cups you can supposedly get aberrant readings from kinking.

[Schewe]

(240cd/m2 last summer)...

Really? Are you working in direct sunlight? 240 is way high...I run mine in a decently lit room at 180 cd/m2 and many people are running them at 140 cd/m2. This may be the root of the change over time...you're kinda burning the LCD...

You can set SpectraView to use any luminance target range you want and I would suggest dialing that thing down a bit. BTW do you print? Do your prints look dark? That's typical of a display that is too bright.

[Steve Weldon]

Really? Are you working in direct sunlight? 240 is way high...I run mine in a decently lit room at 180 cd/m2 and many people are running them at 140 cd/m2. This may be the root of the change over time...you're kinda burning the LCD...

You can set SpectraView to use any luminance target range you want and I would suggest dialing that thing down a bit. BTW do you print? Do your prints look dark? That's typical of a display that is too bright.

+1

[Ken Bennett]

Thanks for the replies. The 240cd/m2 was chosen because I do not print at the studio, but all of my images are made available to our web developers and graphic designers. After experimenting with lower illumination levels, I chose 240 because it made the best match with the end uses of the photos. My monitor at home, where I print my personal work, is calibrated to 140 and it's fine. My prints do not look dark, and the CMYK files made from my images processed on the brighter monitor print perfectly.

So you are saying that this display can't hold 240cd/m2 after 18 months? I will try calibrating at a lower brightness level and see if the other numbers get back in line.

Thank you.

[Tim Lookingbill]

Thanks for the replies. The 240cd/m2 was chosen because I do not print at the studio, but all of my images are made available to our web developers and graphic designers. After experimenting with lower illumination levels, I chose 240 because it made the best match with the end uses of the photos. My monitor at home, where I print my personal work, is calibrated to 140 and it's fine. My prints do not look dark, and the CMYK files made from my images processed on the brighter monitor print perfectly.

So you are saying that this display can't hold 240cd/m2 after 18 months? I will try calibrating at a lower brightness level and see if the other numbers get back in line.

Thank you.

So much for ISO standards. One of these days we're going to get our TV's, mobile devices, computer monitors and home lighting to all be set at the same illumination level.

You do know folks who surf and buy products on the web all have their monitors set to different illuminant levels, right? Just because some "graphics/web design" department is setting there's to emulate what it must be like to live on the sun doesn't mean it's correct or healthy with regards to eyestrain.

[Ken Bennett]

The display calibrated nicely at 180. I'll try that for a while and see what happens.

Thanks to those who provided helpful advice.

[digitaldog]

So you are saying that this display can't hold 240cd/m2 after 18 months? I will try calibrating at a lower brightness level and see if the other numbers get back in line.

The higher you drive a display, the less time it takes to drive down the CCFL.

[bill t.]

FWIW I think the NEC 2690 can ramp down the CFL drive in hardware to a few different levels to best fit the desired brightness.  But that requires the special knowledge Spectraview has about the NEC electronics.  Theoretically that should make for longer life when running at low brightness, which sort of makes SVII worth the price when running at low brightnesses.

I believe that for most LCD displays that you have to calibrate manually, for low brightnesses the numbers that are fed to the monitor are scaled down into rather small values, while maintaining the actual CFL lighting at max.  Would theoretically result in increased integer roundoff errors at low illumination levels, but not increased lifespan.

I really don't like my clients to see the images on super bright screens, mostly because of the apparent increase in contrast.  That promises too much over a print!

Also FWIW I calibrated an LED IPS monitor a few days ago.  Saw the most tortured looking compensation curves I have ever seen, although the screen looks fine.

[howardm]

yes, on my 08 vintage iMac, once you get the CCFLs down to their lowest level, CEDP or BasICC bring the luminance down by bringing down the slope of the curves.  I forget offhand what the final value was for the 255 point but I was throwing away something like 1/3 of the total range.

[WombatHorror]

Really? Are you working in direct sunlight? 240 is way high...I run mine in a decently lit room at 180 cd/m2 and many people are running them at 140 cd/m2. This may be the root of the change over time...you're kinda burning the LCD...

You can set SpectraView to use any luminance target range you want and I would suggest dialing that thing down a bit. BTW do you print? Do your prints look dark? That's typical of a display that is too bright.

yeah 240 is pretty intense, I believe that really shortens the life of a screen

i usually use 80 cd/m^2 in a dark room at night and raise it up to 120 cd/m^2 in a bright sunny room