You are right about that. What I ment was that I could adjust the gamma with the controls available and obtain a graph with mostly perfect gamma response - according to the patterns I use of course.
I used APL patterns from the AVCHD disc which is what I have heard is the best for grayscale/gamma adjustments. For color window patterns are believed as the best. Although I am unsure of what size. Mayby you have an insight on this?
There are many voices on what is the preferred patterns though... János, Tóth F. skrev 2012-02-11 15:31:
No, gamma is far from perfect. Try to measure the grayscale with very small, normal and full screen patches. You will get three different gamma curves and only standard windows size will give you an approximately good enough pure-power gamma function. The same goes for the separate red, green, blue gradients. They all depend on the pattern size and they never really follow the same tonal response (only "close enough"). 2012/2/10 Kristian Jörg<krjg@xxxxxxx>:Thanks for the answers regarding profiling. I will not profile the plasma as a PC monitor. About the VT30 I tend to agree. I just learned that there is a special firmware that improves color luminance on higher panel brightness. This patch is "only" for professional calibrators, and only for the US region. Although it is freely downloadable. I could not find a EU version of it... I also learned that there will not be further patching done as the VT50 model is imminent. :( :( However I do feel that the controls are effective in what they should do. The problem is that the CMS controls one point. The rest of the intensity levels are not following suite... I ended up with a calibration that is no better than the builtin THX. Which in turn has the same color linearity errors as my own calibration. Sigh... VT30: Grayscale and gamma can be perfect. Colors - no. I hope I am wrong. János, Tóth F. skrev 2012-02-10 15:12:I was mad about the VT30E, I said I would never see one of those again after I tried to calibrate one. But interestingly, the G30E is not that bad. The peak error is under dE2000=5, the average is acceptable. VT30 -> Way too much manual controls to achieve effectively nothing or make everything worse. And many manual controls are there to mask the errors in the color calculations (like secondary color adjustments). It's a dead end! 2012/2/10 János, Tóth F.<janos666@xxxxxxxxxx>:XYZ and Lab profiles can do that. But you need to measure a lot of points and there is a big problem with plasma: Average Brightness Limiter. It rescales the gradient, causing tonal response and other color fluctuations. You can't correct for that. If you profile your display with small windows patterns, those will measure nicely through the profile evaluation but you will get high errors with bigger window sizes using the same profile. It would require a huge and power-hungry 4D LUT processing to correct for that (built from an insane amount of measurements). 2012/2/10 Kristian Jörg<krjg@xxxxxxx>:I have a question regarding monitor profiling versus calibrating HomeTheater displays. When I calibrate my Panasonic VT30 plasma (not connected to a PC) with an external program i.e ChromaPure I get dE errors in the range of 1.0 or less. The color calibration is done at 100% stimulus. But when I check the color balance at 75% stimulus I get errors of about 10 dE! Ouch! There is no way of correcting that in the TV set's controls even though it has a very thorough CMS module. The question is when profiling a PC display with Argyll (or similar profiling software), does it correct color at different levels of stimulus or only at 100%? I.e if I would us my TV set as a PC monitor would the profile correct the color balance from 0-100% stimulus?
