monitor calibration
/forum/topic/1169944/0



ejprebis
Registered: Nov 29, 2012
Total Posts: 2
Country: United States

Hello Folks--
Deciding it was time to upgrade from my creaky LaCie 22” crt, I have just popped for a NEC PA271W-BK-SV. And managed to greatly overstep both my skill level and budget. I have been using Photoshop, shooting RAW and Adobe RGB.

aRGB is not one of the gamuts offered in NEC's start-up auto-calibration window (Spectraview II, version 1.1.09; build 111001), so for the time being I’ve settled for sRGB. But some of the calbrated numbers seem to differ significantly. With only a very limited understanding of gamut, though, I could be wrong. For example, five calibrations, done over a 90-minute period, produced these results: (ambient light luminance was 8 lux, color temp 2900K.) I am using a MacBook 15", connected to the monitor via Apple's mini-display port and NEC’s USB cable.

#1. white pt: 6543; dE: .36; luminance: .31 cd/m, intensity: 259.6 cd/m; gamma: 2.2; colors: R=.640, .330; G= .300, .600; B= .150, .060; contrast ratio: 842.1; color tracking: grayscale dE= avg .55, max .83; incl dark values: avg .68, max 1.43

#2. white pt: 6507; dE: .11; luminance: .34 cd/m, intensity: 334.0 cd/m; gamma: 2.2; colors: R=.640, .330; G= .300, .600; B= .150, .060; contrast ratio: 971.1; color tracking: grayscale dE= avg .54, max .80; incl dark values: avg .65, max 1.42

#3. white pt: 6591; dE: 1.92; luminance: .33 cd/m, intensity: 254.3 cd/m; gamma: 2.2; colors: R=.640, .330; G= .300, .600; B= .150, .060; contrast ratio: 842.1; color tracking: grayscale dE= avg 1.60, max 1.92; incl dark values: avg 1.56, max 1.92

#4. white pt: 6514; dE: .46; luminance: .33 cd/m, intensity: 338.3 cd/m; gamma: 2.2; colors: R=.640, .330; G= .300, .600; B= .150, .060; contrast ratio: 1019.1; color tracking: grayscale dE= avg ..69, max .90; incl dark values: avg .76, max 1.24

#5. white pt: 6496; dE: .63; luminance: .34 cd/m, intensity: 335.7 cd/m; gamma: 2.2; colors: R=.640, .330; G= .300, .600; B= .150, .060; contrast ratio: 998.1; color tracking: grayscale dE= avg .67, max .88; incl dark values: avg .75, max 1.18.

The numbers out of step are dE and contrast ratio, and #3’s color tracking. (In their tests, TFTCentral shows a range of 500-600 for contrast, but those numbers are about two years old.)

So—are these shifts “normal” –what one might expect--or is something else going on?

Last question: Where do I find the calibration for aRGB? Would that be done manually?
Many thanks for any advice you can give me! John



Hendrik
Registered: Jul 21, 2002
Total Posts: 3906
Country: Netherlands

Adobe RGB, sRGB, ProPhoto RGB are working color spaces, they have nothing to do with your monitor profiling.

This PDF I wrote many years ago, still contains some good information: http://www.fredmiranda.com/forum/WGuidelines.pdf

Use Google for some more information.



ejprebis
Registered: Nov 29, 2012
Total Posts: 2
Country: United States

Hendrik: Many thanks for your point re monitor profiling and link to your pdf!



halie
Registered: Jan 12, 2006
Total Posts: 940
Country: United States

Thanks, added to ibooks for later reading.