AVS Forum banner
1 - 2 of 2 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter · #1 ·
I've noticed this strange issue with my 42" 800U - hooked up to a PS3.


I can calibrate the grayscale at 30 IRE and 80IRE to near perfect RGB levels with my Eye One and HCFR.


But when I go to 60 IRE, there's a huge jump in blue levels to around 109%. I can't get rid of the blue hump.


I think this issue might be related to the weird color-flicker/false contour problem people have been seeing in the 80/85/800U models.


Changing the contrast levels clearly affects the grayscale, but I can never get rid of this weird color abnormality - the blue hump just shifts to another IRE level - sometimes 50, sometimes 70.


It's really evident in Blu-rays like Sin City (since it's mostly black and white) and Miami Vice (facial tones have weird color blotches). Scenes with clouds or smoke are also a problem.


Anyone have any advice? Do I have a bum panel? Should I get Panasonic to look at it?
 

·
Banned
Joined
·
3,587 Posts
You are seeing typical grayscale performance for your vintage of Panasonic plasma. It is normal/typical for their grayscale to jump around quite a bit from step to step - though it's possible you changed some settings enough to make things worse. I would recommend going back to the factory settings, and re-starting from there. Leave green alone and adjust only red and blue (all 3 cuts are usually set to 80 from the factory... do not set red or blue below 80 and leave green set to 80 unless it has to be moved -- do not set any gain higher than FC). It's also typical for this vintage of Panasonic to have 1 or 2 steps with an error that's very difficult to make disappear. And it is completely typical for the step with the worst problem to change around as you make attempts to minimize errors.


30 and 80 are NOT the be-all-end-all of calibration. In fact, they are barely the starting point. You must measure and consider every step from 10%-100%. The art of calibration is getting all the steps from 10% to 100% to have the smallest errors possible. That almost always means making 30 and 80 less accurate in order to get more accuracy at steps that have larger errors. Green errors are more obvious than any other... avoid green errors at all costs. Red errors are next easiest to see. Blue errors are the least obvious errors and have to be larger than green or red errors to be visible.


You need to be looking at an RGB Levels graph for 10% to 100% to see what each color is doing at each grayscale step. It's not a good calibration if 30 and 80 have zero error but every other step has dE errors of 10 to 20 (or more). You may have to settle for errors of "5" at 30 and 80 to keep errors at other steps from being more than "5" -- but every TV is different.


Your PS3 needs to have 2.5 or higher firmware on it... some earlier firmware versions changed the data read from the disc.
 
1 - 2 of 2 Posts
Top