Black levels aren’t (this) negative with any model i heard of. It’s a more of a QOL enhancers for some games.
Ofc. shader parameters can be cranked up, but you can use like as this also:
The image adjustment implementation messes with saturation, it’s a simple substractive implementation with some correctures.
One has to be a bit specific here, or feedback can become very confusing.
Hi, I’m new here, I love this post, and You are Doing a Good Job, I think is the best Shader in retroarch. here I’m gonna post some pics in 4K
. This is how it looks. I tried to copy my 14" CRT Sanyo TV…I can’t make it look good, no matter what I try 
The main issue is preserving the relative brightness between things. The simple black level adjustment from image-adjustment just works better for me:
After changing black level in the image-adjustment.slang settings, I can then use the guest advanced settings for bloom, contrast, etc and I get what seems to be an accurate result. The castle is bright, the mountain underneath is darker, the stone walls are brighter… This matches the brightness differences from the photo of the arcade machine. In your screenshot, everything has the same brightness. It’s very flat.
It’s intentional though…thought folks want to keep saturation intact. 
I think got it now, will post an update.
New Release Version (2022-07-02-r3):
Notable changes:
Download link:
https://mega.nz/file/cwYTVb6b#fijzZsfjrckt304uyyhcZulMZ1vGqs2-uD7P3d6nbb0
That’s pretty much perfect! And it allows the rest of the shader parameters to come to life.
Small nitpick: The parameter should probably be called “Adjust Black Level” (or “Change”) rather than “Raise”
Hey @RetroGames4K, welcome to the forum. Glad you like the shader and feel free to post some nice screenies. You can also post the parameter values from the custom preset, so other users might benefit from your settings. And happy tweaking. 
I also like it better now. Always found some arcade games a bit dull in colors. I think the new option can help here without turning the other parameters upside-down.
Thanks a lot. Thanks to this shader I could copy the pattern of my CRT Sanyo tv. And it looks really close. Here is an example of a sega saturn game. Real vs emulation…
Nice pics. 4k needs different tweaking, but opens more options also.
Meanwhile i forgot to mention that Mask Bloom functions very well with the Mask Gamma functionality, while it doesn’t make a difference with ordinary Bloom, at least with masks at full strength.
It also preserves NTSC artifacting better.
Feel like i need to mention this if someone is after a setup which includes Mask Bloom.
Screenie:
Thanks, I’m glad you like the pics😁. I already use mask bloom at 0.75 and normal bloom 0.0, and I lower down the bloom sigma to 0.35,because my CRT doesn’t make that foggy effect, it looks more crisp similar to My CRT. I’ll try to make a side by side pics, If I can later tonight so you can compare…
Here are the comparison of Shader 4K vs Real Sanyo CRT, the colour looks similar, but the shot of the crt was taken with the camera from the mobile phone and it gets a bit brighter and the colours looks less pronunciated, but in reality looks so close…
Incredible! This is so beautiful it’s faithful!!
Thanks, I’ve been trying for hours to make it look alike. And it was hard. But finally did it. Then I found this forum And I relize that there was an updated version. The new function of bloom mask is what it made almost identical to my CRT sanyo. I’ll make a gameplay soon and I’ll post it here…
By the way, the image above, the CRT looks stretched, because My sega Saturn Console is Pal… It would be nice to have a pal mode and an option of RGB like Blargg’s because the blacks are more blacks in snes and mega drive with that option.
I took some macro shots of one of my presets with different mask settings running on my LG 55OLEDE6P.
I’m hoping that they might be able to assist in creating an improved colour Mask for WOLED TVs.
What I’m observing in my screenshots looks something like this:
GXXGXBXXBRXXRXXX or GXXGXBXXBRXXRXXXX
On the Slot Mask pictures it looks as if the right half of the Blue Subpixel overlaps with the Top left and Bottom Left halves of the Red Subpixel to the right of it.
Mask 6, Size 2, Layout 0
Slot Mask Height 2, Slot Mask Width 3
Sonic The Hedgehog Sega Logo, White Background
Mask 6, Size 1, Layout 0
I guess the last two screenshots explain why the image still looks good on OLED despite it having a strange subpixel arrangement and alignment.
Am I seeing XGBR or XXGBR output here?
On further investigation, it seems like RXGB. At other mask sizes, I’ve seen RRRGGBB. I’ve also seen XXGGGBB (not on white though).
Sony Megatron CVM SDR
Apparently not all WOLED (RGBW) TV’s subpixels are the same after all. From the 2018 models, LG Display increased the size of the red subpixel by 80% as a burn-in reduction feature.
Very interesting. Looks like the gap between Red and Green is where the white subpixel should be, or am I mistaken?
I’m really not sure, this is the output after the masks are applied so that would probably alter the final colour shown. The gaps could also be where they are due to some misalignment between the mask and the subpixels.
I’ll let the experts answer that one.
I’m going to add a macro picture of a pure white background at native resolution in order to try to show the actual subpixel layout of the screen.
Also remember that this is Mask 6, Size 2 so it’s not going to be subpixel accurate as 2 pixels are being used to represent each RGB “phosphor”.
I know subpixel accurate RGB masks are out of the question for WOLED displays but I’m wondering if anything can be done to improve the coarser 2 pixel per “phosphor” variety.
