TV backlight compensation (2020)

Now manufacturers are possibly prioritizing the highest grade panels for non-gaming use and using extremely expensive gaming monitors as a dumping ground for everything else.

For example, the 28" UR55 has few complaints about backlight bleed and in my experience with having bought several is a reliable choice. Meanwhile the oddly similar 28" Odyssey G8 is known as a "buy and return until you get one that's ok" type of monitor, as are many other gaming monitors these days.

Gamers seem conditioned to just accept inferior panel quality as long as the other specs work, while business and casual customers would probably just buy another monitor if they saw weird issues. They might not know the term backlight bleed, so they'll still see it just fine.

The constant ramping of brightness is rather distracting.

That is at least the explanation I got on some obscure forum where someone else had a similar problem and it was caused by heat.

> is the tape oriented diagonally?

Worse - it's a multi layer sandwich of filters etc. which need to be perfectly aligned for a clear image:

https://www.azom.com/images/Article_Images/ImageForArticle_2...

Funny thing is in my case the hottest part actually remained ok - it's the surroundings that got, for lack of a better word, ruffled.

I've seen videos of Indian repair men disassembling a panel and putting it together to fix such issues, but IIRC only the back light ever came off.

Just looking at the pictures, this does not look like a backlight problem but rather degradation of the liquid crystal layer. Yes, sure, there's interaction between the two. The purple shift, however, is very much something that was happening twenty years ago with some liquid crystal chemistries. Back then you could definitely tell which panels were not using high quality LC fluid.

Apple had this issue with their second generation HD Cinema Display product (the first aluminum enclosure, 24 in, 1920 x 1200 model). Some percentage of them would turn purple. I don't have Apple's stats on this. From my own experience the number fluctuated between 15% to as much of 50% of the panels in a batch going bad after moderate burn-in.

Having said all that, this type of compensation or fix might be OK for a TV at home or the computer monitor on the desk of a doctor or even a coder. Not good --at all-- for someone doing critical color work, such as a graphic artist. The reason is that you introduce spatial nonlinearities and differential errors.

The simplest way to put it is that you no-longer have the full 256 (or 1024) steps per R, G, B channel between 0 and 100%. Hypothetically, you might have 256 for green and, say, 200 for red and 175 for blue. This means that the path from black to white is no longer monotonic. You can have serious color rendering errors through the color space. For example, it might be impossible to make an accurate 50% gray because you just don't have the RGB values needed to accomplish that. Worse yet, everything between 47% and 53% gray might look exactly the same.

You can also introduce serious gamma distortion. If, on top of that, you add a temporal element (video), well, it can be a real mess.

The real solution (for critical workflows) is to replace the panel.

BTW, this can apply to RGB OLED as well.