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I am a big fan of DisplayCAL/Argyll.
Today, I ran a fresh calibration on my 43″ Dell LED U4320Q monitor.
When the calibration was complete, I opened up the Tool > Show curves dialog.
I selected “Calibration curve” in the menu. See attached screen capture.
Please forgive my ignorance but I thought, naively perhaps, that calibration curves, who later are encoded in the VCGT tag and downloaded in the Video RAM (“gammaramp” on Windows) were created not only to make R=G=B “neutral”, relative to the monitor white point but also implement the chose gamma or Tone Reproduction Curve?
As you can see from the capture, I highligthed the area at the bottom of the capture where the cursor is pointing in the graph.
So for R=G=B=128, the RGB values are 131.93 135.79 and 137.40. Which, according to DisplayCAL correspond to a RGB gamma of 0.96, 0.91 and 0.90.
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This is where I have “lost you”, DisplayCAL…
Having chosen a target gamma of 2.2, I was under the impression that the RGB ramps would be adjusted such that their combined RGB values would yield “2.2”.
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Looking at the Tone Response Curves, I get that the resultant gamma is 2.2.
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Please forgive my ignorance!!I am a big fan of DisplayCAL/Argyll.
Today, I ran a fresh calibration on my 43″ Dell LED U4320Q monitor.
When the calibration was complete, I opened up the Tool > Show curves dialog.
I selected “Calibration curve” in the menu. See attached screen capture.
Please forgive my ignorance but I thought, naively perhaps, that calibration curves, who later are encoded in the VCGT tag and downloaded in the Video RAM (“gammaramp” on Windows) were created not only to make R=G=B “neutral”, relative to the monitor white point but also implement the chose gamma or Tone Reproduction Curve?Yes, grey color + “gamma” in 1d lut
As you can see from the capture, I highligthed the area at the bottom of the capture where the cursor is pointing in the graph.
So for R=G=B=128, the RGB values are 131.93 135.79 and 137.40. Which, according to DisplayCAL correspond to a RGB gamma of 0.96, 0.91 and 0.90.gamma relative to linear ramp, as in GPU driver. This is not monitor gamma.
–
This is where I have “lost you”, DisplayCAL…
Having chosen a target gamma of 2.2, I was under the impression that the RGB ramps would be adjusted such that their combined RGB values would yield “2.2”.
–
Looking at the Tone Response Curves, I get that the resultant gamma is 2.2.
–
Please forgive my ignorance!!Gamma 2.2 means that the luminance of the display output (normalized to 1) follows the x^2.2 function.
The VCGT RGB values are the signal levels needed for that display to output the right amount of light to follow 2.2 gamma
