Originally Posted by Geof
I wonder if part of the saturation tracking issue isn't due to "profiling a profile". Certainly the color profiles are adjusting gains and offsets as well as color coordinates and it seems to me that calibrating over the top of that is only going to be linear over a very narrow correction range. I definitely believe there is an undesired interaction when doing this and saturation tracking errors seem like a plausible result. Limiting the "correction profile" (ie user calibration) by choosing a close profile to start with makes sense. I wonder though how well the CMS would work if one could start out with no profile.
The saturations tracking issue is possibly due to calibrating from a profile, unfortunately calibrating without a profile is not an option, as when you switch the profile off all the other options (including CMS, gamma, greyscale) etc are not available anymore.
Selecting a profile has no effect on gamma or greyscale, it only selects the "native" colorspace you are going to calibrate from.
An external VP may not even be an option with color profile "off", as you have no way to get white at 100% right, and the gamut may be too wide to be corrected anyway.
Originally Posted by millerwill
The advice you received from others above seems good from all the reports I've seen here in the Forum; i.e., 1. seems like probably the best (the slightly lower o/f CR of the 40 vs the 50 will probably not be a serious shortcoming unless your room is nearly a perfect black hole).
I am still with my RS20 (i.e., 'waiting til next yr' to upgrade) and its CMS, though not perfect, performs (using ChromaPure) considerably better than that in the newer RS50 (at least from what I read here).
I agree that there is little point in buying an rs50 or rs60 if your room is not dedicated, however having compared the two, I disagree about the statement regarding the rs20 offering better colour performance than the rs50.
Calibrate your rs20 with Chromapure and measure the saturations with the advanced color management module. You will see that the way they track is far from perfect. Not as bad as the rs50 when applying too much corrections with the CMS, but much worse than the standard colour profile on the rs50/60 which is incredibly close to the standard (much better than THX on the rs20) and tracks in a perfectly linear way. If it is slightly undersaturated, bumping color up to add a bit of luminance to compensate the slight lack of saturation allows to get a much better result (from a color gamut point of view) than a calibrated rs20. The uncorrected color profiles track in a perfectly linear way, both regarding stimulus and saturation. Again, if you are targetting rec-709, the CMS issue on the rs50/60 is a non issue if you know what you are doing or if you take the time to read the calibration thread.
Originally Posted by krichter1
So then Manni when I redo my calibration today do you think I should stick with Standard CP or move to Stage at this point (I'll start w/ 2.3 gamma as you instructed me the other day)? Will HCFR have any issues w/ the Stage CP when trying to fiddle with color for 75% stim?
I would stick to the standard color profile for now, and see what you get when working on the greyscale with the gains at 100IRE, as this may improve your gamut. You need to get greyscale/gamma right before starting fiddling with gamut, especially with the CMS of the rs50 as it is now. Hopefully your gamut will be fine, and if it isn't just try to play with the main color control to lower the dEs (take red, and move the color control one notch at a time, seing if your dE goes down or not. It is likely to go down up to a point, then go back up again. In my case the sweet spot is around 2-3). You are likely to get infinitely better results than by playing with the CMS in its present state.
As I suggested in the other thread, select a custom gamma with a 2.3 default before working on the greyscale, and if after your greyscale calibration your curve is still going too low in the high end, try to play with the dark/light adjustment to correct higher part of the gamma curve.