9 point gamma question

[mpcengineering]

Hi all,

So, got hold of ControlCAL a couple of days ago and working well on our UK 5090 panels, but I have a quick question about the 9 point gamma controls. I understand this is designed to replace the gamma presets available from the normal user presets but to me, it seems more like a fine adjustment of the RGB high/low from 10 through to 90 IRE in which case I would relate this more to the white point.

The reason I ask is because having made a white point adjustment with RGB high/low, the luminance values along the greyscale point to a gamma of around 1.9 rather than 2.2. So this would suggest to me as there are no longer presets for gamma, the luminance adjustment needs to be done at the same time as setting the white point with RGB high/low, and then the luminance and white point values tweaked with the 9 point gamma adjustments. Do I have the right end of the stick?

Cheers

Jon

[Turbe]

7/26/2009 - CURRENT 9G PIONEER ISFccc CALIBRATION WORKFLOW (Posted Here (http://www.avsforum.com/avs-vb/showthread.php?p=16891652#post16891652))
by D-Nice


Set peak luminance (Contrast)
Set black level (Brightness)
Adjust grayscale (RGB High/Low)
Adjust CMS
Adjust Gamma
Tweak grayscale (RGB High/Low and CMS)
Adjust Color
Repeat steps 1, 3, 4, 6 and 7 until grayscale and color points are maximized




7/26/2009 - OUTDATED
ISFccc Workflow for the 9G Pioneer (D-Nice).


Set peak luminance (Contrast)
Set black level (Brightness)
Correct grayscale (RGB High/Low)
Fix gamma (9 point gamma controls.....green first followed by red then blue)
Correct color points (CMS controls)
Tweak grayscale (RGB High/Low)
Verify grayscale, gamma, and color points again
Set color saturation (Color)


This is similar to Wolfy's Workflow (http://www.controlcal.com/forum/showpost.php?p=970&postcount=13) used on the 8G's.

:thumbup:

[mpcengineering]

Ok thanks, so from wolfy's post it looks like he is also working to the assumption that the 9 point gamma readings are for fine tuning the white point over the greyscale but also obviously will affect the luminance. My initial attempts at using the gamma adjustments to make the white point and luminance accurate across the greyscale resulted in severely inaccurate whites which could not be corrected by any tweaking of the top end gamma adjustments - this was after an initial white point adjustment with RGB high/low. HOWEVER, I did not make much, if any adjustment to the luminance with RGB high/low, so I shall try this time with a luminance adjustment made along with the white point adjustment before tweaking this with the 9 point gamma controls.