Quote:
Originally Posted by airscapes 
Luminance and RGB are 2 different things. The meter can read the proper brightness (amount of light or luminance) correctly but not the proper color.
Gamma is the difference in luminance form 0 -100% and has nothing to do with color, so it can be accurate and the color reading be very wrong. You can not fix this without using a known good reference spectror meter, and if you had such a meter, you would probably just toss the D2 in the trash and use the spectro since the speed difference would be of no great issue.
Then you display a Red, Green, Blue and white pattern and take readings of each.
The software makes a table of the difference between what the reference meter sees vs what the target meter sees.

Luminance and RGB are 2 different things. The meter can read the proper brightness (amount of light or luminance) correctly but not the proper color.
Gamma is the difference in luminance form 0 -100% and has nothing to do with color, so it can be accurate and the color reading be very wrong. You can not fix this without using a known good reference spectror meter, and if you had such a meter, you would probably just toss the D2 in the trash and use the spectro since the speed difference would be of no great issue.
Then you display a Red, Green, Blue and white pattern and take readings of each.
The software makes a table of the difference between what the reference meter sees vs what the target meter sees.
Well, the gamma data is based on relative brightness levels so if the absolute level is off that would not affect the delta % values. Therefore, if everything is still linear, then the gamma before and after should look the same.
However, I'm having trouble with the luminance vs RGB levels. The luminance plot I have (see above) has all 3 colors displayed - not the luminance only plot. Therefore, if RED is low shouldn't it show up as low on the RED color luminance chart?
BTW does the i1 Display 2/LT have 3 or four sensors in it? I see the 3 RGB filters, but what is in the 4th hole? Is that a luminance sensor?
The profile procedure then only uses a single white point and the 3 primary colors RGB at a single stimulus (like 75%) to calculate a matrix to stretch or push the meter's (to be profiled) color space to match the reference meter. If things are linear this would appear to correct things. However, if things are not linear is this sufficient. Does the software require a full meter comparison after these 4 measurments to ensure accuracy across the board from low to high saturations and luminance values? The 2 meters should match for all readings not just the initial white and primary values.



















