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Author Topic: i Pro, NEC i1D2 and i1 Display Pro readings on NEC PA241W  (Read 1786 times)


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i Pro, NEC i1D2 and i1 Display Pro readings on NEC PA241W
« on: January 13, 2012, 07:03:41 PM »

Actually here are readings I got, just for kicks:

first with the monitor set to native gamut, RGB primary xy values only:

According to factory settings it should be (at least when new and it's far from now):
R .678,.312
G .200,.694
B .152,.054

"( )" are deltas from factory setting claims

With i1 Pro:
R .679,.309 (.001,.003)
G .214,.690 (.014,.004)
B .152,.056 (.000,.002)

With NEC i1D2:
R .683,.306 (.005,.006)
G .214,.691 (.014,.003)
B .152,.057 (.000,.003)

With i1 Display Pro:
R .679,.308 (.001,.004)
G .207,.694 (.007,.000)
B .152,.054 (.000,.000)

i1 D Pro is closest to original factory readings, still off on green, but much closer than with the other probes, only red y is worse than i1 pro (this assumes zero drift, the monitor does have a TON of hours on it). The i1 Pro and i1D2 from NEC are actually quite close or identical other than when it comes to reading the red primary (and maybe white point, forget to write the WP stuff down for native mode).

now for when it was in a modified sRGB emulation mode I list here the factory claims as the mode had been programmed (it doesn't match to probe measured ideal primary locations and WP since I hadn't recalibrated this mode for like 8 weeks):
factory settings claim it should read:
WP .307,.327
R .638,.333
G .291,.602
B .150 (take it as .152 though since the PA can not actually hit below .152),.057
again "( )" are deltas to the factory settings, note that the set has been used a lot so some drift is to be expected, especially for the WP so the factory claims are not necessarily the ideal goal, a slight bias in that direction might hint at the more accurate direction(?)
NEC i1D2 before being warmed up:
WP .319,.335,94.8 (.012,.008)
R .645,.327 (.007,.005)
G .303,.600 (.012,.002)
B .152,.063 (.000,.006)

NEC i1D2 after sitting on the screen for 20 mins and then being continuous read from for about 20-25min (the latter seemed to help it warm up much more than the former):
WP .316,.331,94.45 (.009,.004) [delta to pre-warmup a significant .003,.004]
R .644,.327 (.006,.005) [delta to pre-warmup .001,.000]
G .3025,.600 (.0115,.002) [.0005,.000]
B .152,.062 (.000,.005) [.000,.0001]

So warming up an i1D2 makes little difference when it comes to measuring the primaries but a significant difference when it comes to reading the white point.
i1 Pro:
WP .315,.3325,95.4 (.008,.0055)
R .640,.329,20.43 (.002,.004)
G .302,.600,68.8 (.011,.002)
B .152,.062,7.1 (.000,.005)

The i1 Pro readings are nearly the same as the NEC i1 D2 readings other than for the red primary). They are still closer than I thought, when I first started writing I hadn't done the warmed up values yet.
i1 Display Pro with no warm-up:
WP .311,.329,92.6 (.004,.002)
R .640,.329,19.8 (.002,.004)
G .296,.603,67.4 (.005,.001)
B .152,.059,6.72 (.000,.002)

i1 Display Pro after 10+ minutes of continuous read warm-up:
WP .3095,.327,92.9 (.0025,.000)
R .639,.329,19.72 (.001,.004)
G .2955,.6015,66.96 (.0045,.0005)
B .152,.058,6.73 (.000,.001)

So the i1 Display Pro read things as being darker than the other two with the i1 Pro have the brightess take on things. The i1 Display Pro readings were closer to factory measurement expectations (although after so much usage who knows what the ideal is).
The i1 Display Pro seems to read best after about 10 min of continously reading to warm it up after a real lot of non-stop usage for a long time it might start drifting a bit too far, not sure.
It basically read the same as the factory for the primaries other than for green x and red y and both of the other probes read those values differently too and in the same direction of different although the other two read the green x as being much more different, for the red y all teh probes agreed with eachother and not with the factory measurement at this point.
For kicks here are DTP94b readings without matrix compensation (or warm up):
coloreyes older copy:
WP .331,.333,92 (.024,.006)
R .642,.330 (.004,.003)
G .318,.589 (.027,.013)
B .155,.063 (.003,.006)

newer copy from and said to have been calibrated by spectracal:
WP .329,.331,90.5 (.022,.004)
R .642,.331 (.004,.002)
G .315,.592 (.024,.010)
B .153,.062 (.001,.005)

This one had slightly lower deltas but still in no agreement at all whatsoever about green primary or the white point with any of the other probe types or with the factory calimed values, although R and B primary readings were no more out of the ordinary than with some of the other probes and actually it read the red primary even closer to the factory setting than the compensated NEC i1D2 and about the same when it came to the B primary.
The DTP94b read the white point darker than any of the other probes, especially the spectracal calibrated one (maybe their filters block too much green light?), although the coloreyes one was close to the i1 Display Pro brightness readings.
Without a $30,000 reference measuring the screen as it is now, I'm left to guessing and speculating about things though.

I believe I have the values measured when the set was new, written down somewhere. I wonder if they show any evidence of Green x or Red y drift over time. Not sure where they are but I must have them somewhere.

I wonder if the i1 Display Pro WP readings, closer to the original factory setting is more accurate or the i1D2 and i1Pro which agree with each other almost exactly but differ somewhat noticeably from the i1 Display Pro. I tend to lean toward trusting the i1 Display Pro more for a few reasons but I could easily prove to be mistaken in that.
It would be interesting to see what another copy or two of each of the probes would say and if any sort of pattern would emerge and most interesting to be lent a $30,000 probe for a day .

The .000x decimal place values were used when the reported value would oscillate back and forth between the a reading .0005 below and above.
« Last Edit: January 13, 2012, 07:06:54 PM by LarryBaum »


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Re: i Pro, NEC i1D2 and i1 Display Pro readings on NEC PA241W
« Reply #1 on: January 15, 2012, 02:43:21 PM »

(as brought up by Will, xyY does exaggerate differences in green compared to differences in blue and red)
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