Question WebOS 4 & Colour Management System problem

Tamadite

Novice Member
Joined
Oct 13, 2018
Messages
4
Reaction score
1
Points
1
Age
43
Location
Sweden
Model: UK6300PLB
WebOs: 04.10.04

I have found problems calibrating the luminance of the secondary colours (CYM). For some reason neither the luminance nor the saturation respond to the change in values, only the tint does. The situation I have now is that although the primary colours (RGB) are perfectly matching the REC.709 specs, the secondary colors do not reach the expected luminance that is, they are underrated.

Any hint?
 
Unfortunately that's often the case with many tv controls. Even with the most expensive sets (e.g. on my c6 oled the cms doesn't work as expected either, and even with hdr, the wb controls stop responding past a certain point).

If you find they're not having the desired effect, best to not use them at all, and just get the picture as accurate as you can without them.
 

You put it exactly right when you say that some options are there for marketing rather than function.

With regards to the software though....have you tried using the normal display profile rather than one of the wrgb ones? I know it sounds wrong, but I think I remember there being some issue with the profiles on hcfr that meant you needed to still use the profile for standard lcd displays? It's been a long time since the days when I was diy calibrating my c6....so I could be totally wrong, but worth trying/looking into?
 
Finally a cold restart of the TV set did the magic! WB and colour gamut is now on the spot (BT.709). Still I have a small deviation on Cyan (dE=2.3).
Next step is to learn HDR calibration... HDR videos on Youtube (HDR gets activated on the TV) look "too good to be true" in the words, the old same thing: high contrast and saturated colours.

The long story:
1) I started to suspect something was wrong (or right) when I saw my daughter watching videos in Youtube. They looked very good! I got squared when I look at the TV profile: it was the profile I had calibrated. This profile turned out to be awful for "live TV" channels.
2) So the same profile resulted to be good for Youtube but awful for "live TV" channels. My head started to spin.... limit vs. full RGB, RGB vs. YcBcR, BT.709 vs BT.609, heaven vs hell.... etc.
3) I decided to do the IT trick before start crying... restart the TV!
4) I checked the WB... just small adjustments which made the parameters not to be overdriven any longer (lowering blue and luminance)
5) I checked the colour gamut... horrible! Completely wrong!!!! Almost no Green, wrong Cyan nuance and weak Yellow. A recalibration of the RGB-YCM having the Red as reference (tweaking the color gauge only) set the Red on the spot: Saturation, Tint and Luminance at cero!
6) Restart the TV and reconfirm everything "was in place"
7) Voilà!

BTW, the display type I used in HCFR was "LCD White LED IPS (WLED AC LG Samsung)"
 
Hopefully the last chapter on this one. I found out a bug on the feature "Quick Start+". It seems like when this feature is active, the colour configuration is not properly loaded and so the "live TV" channels get horrible colours: extreme warm and clipping colours on the edges. A cold restart solves the problem.

The reproduction of the problem (in my case)
1) Activate feature "Quick Start+"
2) Calibrate the TV set (BT.709)
3) Turn the TV set off
4) Turn the TV set on
5) Observe colours on some "live TV" channels, specially analogue
 

The latest video from AVForums

Is Home Theater DEAD in 2024?
Subscribe to our YouTube channel
Back
Top Bottom