Pokefan531's Posts

LEDs with RGBW Breakdown.

This is for demonstration only, to explain about LG TVs with RGBW displays.

I put up this photo to explain why RGBW displays are in worse quality than you think.

I’ve been watching animated content on our 4K TV for nearly a year, and since Day 1, after finding out and playing around with the settings very heavily, the colors doesn’t look right. We see Spongebob almost everyday because, for obvious reasons. However, we know Spongebob is supposed to look yellow and bright.

You can see on the picture on the left of what the image is supposed to look. Most displays, even OLEDs, Plasmas, and Quantom Dot, have only RGB sub-pixels on each pattern. It supposed to look as good as that. Even for a photo hobbyists or professionals, they wouldn’t mind if the color gamut is near the sRGB standard.

However on the middle, this is what RGBW displays really look like when you try to make it bright for your room. It looks off because since it is an RGBW TV, the white will be brighter than the colors almost all the time. RGBW is Red, Green, Blue, and White colors on each pixels. It is not pleasing, and you can notice the difference, especially if you compare other displays that is just RGB. The colors will look darker, so explosions, Spongebob, or objects that should look vibrant, will look fainted on RGBW displays. Only the white will look as bright as it can, so the whites will be a leap ahead throughout the image. As you can see, Mr. Krabs and Spongebob will look a bit fainted, but especially Spongebob looks a bit worse when seeing it on our LG 4K TV. Also, look at the color bars.

I did try to manipulate the colorspace that our TV outputs, but what I can say is that the yellow color has a bit of a green tint. My guess is that the Red, Green, and Blue aren’t trying to be equal to produce the white color with excellent white balance since it has the white light on display. It usually looks worse. I did look at Windows 10 desktop on there and the colors looks garbage. The folders are dark because the colors aren’t caught up with the whites. All the vibrancy are kinda lost in luminance level.

On the right image, that’s if the white color are balanced for the rest of the colors, and as you can see, it looks better than the middle, despite being a bit darker. It looks more correct if you pay attention to the color vibrancy. I get that similar effect on our LG RGBW TV by setting the contrast to 50. It does look better for the colors, but the display is too dark for light day. It’s only good for night time with or without dim lights on the background.

I did increase the brightness to 60 and it does look a little brighter, the black levels raise a little, so you lose a little contrast. However, it looks enough and acceptable for me, so it’s not degraded. When I increase the brightness anything higher than 60, the black levels are gray and the image looks too washed out. I always set the backlight to 100.

The thing is, I’ve been trying for many months to try to make the image to look good. On the contrast levels, when I set to 70-100, the colors looks a lot dark, and only the whites are brighter in those values. Setting it to 60 with the brightness settings above still looks dark a little on the colors. Also, it isn’t enough for light day sometimes. That is not good. I did try to play around the settings on expert mode, and I did max the RGB at the white balance area. It looks almost the same and setting higher than contrast 70 makes the bright colors looks cut off and overclipping.

Also, I did try Color Management and play around the settings. I did brighten the colors as I can. It gives me a better results, sort of. The problem is that it only affects on the Red, Yellow, Green, Cyan, Blue, and Magenta. It doesn’t affect on other colors like Orange, and the calibration between Red and Yellow for example doesn’t transition smoothly, so Orange is left dark. My other problem is that it does not do it frame-by-frame basis. What it does is seek a frame to see what colors should be adjusted, and then it would do the process by half a second. So you would see Yellows on the first frame and it looks dark, but it will look as bright as you want it to be by 0.5 second. You can see this artifact along with color warping artifact too, especially looking at color test and color transitions, and sometimes on rainbows too. My last words is that the contrast should be lower than 80 to prevent color clipping.

So with all the explanation here, I recommend avoiding the RGBW TVs for visual quality. Some reviewers says that RGBW pixels reduces resolution. I don’t believe it because if you plug an HTPC to a 4K RGBW TV, the black thin line as vertical looks slightly fuzzy, but still sharp, and sharper if you look at black horizontal thin line. I still avoid buying those displays for my above statement, especially the entry level ones. It was our mistake to get the LG UJ6450 on Black Friday Deal without massive research. No one mention this color artifacts on RGBW displays. I tried looking for this, but no results. I don’t know if our TV is product defective. It may only look good on HDR mode or presentation on stores, but we can’t test TVs that would touch to our likings, so we won’t know if a specific TV is good. Even trying to look video reviews may not have the video for a specific TV or if a video doesn’t cover everything.

Despits bring against RGBWs, I rather get the display over OLEDs for burn in reasons, if someone wants to play video games for multiple hours and not wanting HUD burn in layed to the screen. Even with great quality OLEDs, I would personally avoid those if the TV will be used in multiple situations.

I know there are higher priced RGBW displays from LG, and I heard that higher ones are brighter and more acceptable for HDR experience. Although, being a RGBW TV, it would still show the color artifacts. If you got the higher ones and if the contrast set to 50 is bright enough or if your LG TV doesn’t have the colors artifacts, if RGBW panel, let me know. I know that those TVs have one frame of lag for games. Also, our display has audio lag, so it’s worse. I notice this on most inputs, even watching YouTube videos too. I tried using PCM audio on both the TV and every devices connected to it, including the TV Box.

That’s all I had to tell based on my experience. I know I can use a colorimeter like Colormunki Display to correct it only on HTPC. It would darken the whites to compensionate the brightness to equal the luminance for the color LEDs. I tried doing something like that on an LUT texture on Photoshop. While it gives me better results with Contrast to 75-100 and brightness to 60 on Retroarch, it is still a mile away from being acceptable, so YMMV.

That’s all.