You are not alone - I get the same black screen behavior when turning on HDR in Retroarch with my LG C1. It seems that anything that causes RA to loose focus when HDR is on causes the black screen issue and RA needs to be restarted.
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Thanks again for your help. The colours do look a little better when i calibrate the luminance in the hdr settings in retroarch, but not as vibrant as sdr. The paper luminance was very low, but i believe the shader overwrites these so i didn’t want to touch them. Hdr is on using vulkan, the whites are brighter, but the shader doesn’t look right. Like there’s a translucent filter. It looks like the max brightness is too low then there’s the oled subpixels too . I’ve seen decent results on a C1 tv though. I’ve tried changing the hdmi input to pc mode, games mode, normal etc and all look different, but none correct. Also tried using a dp to hdmi, but then my max resolution was 1080p. Strangely, dx11 and dx12 don’t have a hdr option at all. Only vulkan does…
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Yeh, RA goes windowed for a second when turning on hdr so has to refocus. Have you managed to get this shader looking ok on your c1?
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Yes this definitely signifies something is up with your HDR. D3D11 and D3D12 are the gold standard when it comes to HDR in RA in Windows. They’re checking for proper support and sending metadata back to the TV etc.
You’re right to ignore the Settings->Video->HDR luminance and contrast settings when using Megatron as it bypasses those as it’s a proper HDR shader.
So my question again is when you toggle Quick Menu->shaders->shader parameters->SDR | HDR do the colours instantly fix themselves in the shader (but it looks a bit dark)? Let me know what option has the right colours - HDR or SDR - SDR will be darker though but thats to be expected.
Ok i got hdr working in dx11 and dx12. Changing to sdr in the shader actually makes the colours very intense and incorrect so i think hdr is working. If i lower paper luminance to around half of the peak then the colours look like they should be ok, but it just can’t break through the mask, going much higher brightens the image but washes it out as i guess the paper luminance shouldn’t be set higher than peak. If i set crt type to 3 it actually looks ok. I’m guessing 3 is a b/w mask? I would just put it down to the subpixels and lackluster luminance, but hopefully someone with better success with oled can chime in
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Ok great stuff sounds like you’re making progress! So that sounds about right paper white about half of peak (I can go all the way up to peak but maybe we’ll get to that).
So you say colours ‘cant break through the mask’ - they aren’t supposed to as thats not how a CRT works. What are you after when you say you that just so I can try to understand the problem youre seeing? If you look at the images at the top of this thread in the first post you should see what an actual CRT does - are you getting anything like that? You should be able to.
Do make sure your ‘sharpness’ settings on your C6 are set to neutral either 0 or 50 usually dependent on the TV.
Mask 3 is a B/W mask and its certainly not how a CRT works or looks (again see above to see comparison shots). By all means use it if thats what you prefer but then its not really what this shader is trying to aim for. Your TV should be perfectly capable of getting pretty close to what a CRT would do. As a bonus your TV will actually naturally add a glow pass to the shader (that other shaders do) as in the white subpixels will get turned on in the highlights adding an extra boost to them alongside your inky blacks.
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If you have the time or patience take a close up shot of your OLED a few inches away with the following settings IS0 100, WB 6500K, Aperture Speed 1/60. Zoom into the picture on your phone and then take screenshot and post that screenshot here so I can see what is going on at the pixel level.
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I guess ‘cant break through the mask’ is a bad choice of words. What I mean is, I’m not sure the TV is bright enough to properly illuminate the image when using the mask. The whites don’t look white in the same way your images show. The b/w mask isn’t ideal, but it isn’t dulling the image in the same way. It’s hard to explain and I don’t have a camera. I’ll try a camera app with manual controls for my phone and see what I can do. Thanks again for your help
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So although screens behave differently on a local level to the whole screen as RTings shows my Eve Spectrum on paper is only a tad brighter (700 vs 650) than your OLED with a much much lower contrast ratio. You should be able to get the brightness required out of it.
If you look at the various videos in the first post are you seeing anything like that?
Maybe what’s going on is that I can put my paper white luminance right up to max where as you can’t because the white sub pixels are kicking in and distorting the colour? Hmm hadn’t thought about that.
Mind you surely that would effect all content. 
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Perhaps you can give us some presets to get the looks that you have been able to achieve on your setups. They can probably be used as a better starting point for some than the defaults.
I didn’t achieve the type of look that I’m seeing in the pics in my initial experiments and my TV hasn’t been reviewed by RTINGS. I just don’t have the time right now to work through the issues.
So I reset my TV to factory calibration (can’t believe I didn’t think of that before) and set the input to PC (4:4:4 chroma) and it’s looking better. Here’s a phone pic with and without the shader, both HDR. There’s a lot of magenta with the shader and the whites don’t quite pop. I can see the resemblance to my PVM when up very close, but the PVM is vibrant and the whites look white from a ‘normal’ distance. It think it does look similar to your videos, but feels like the white sub-pixel is kind of washing out the overall look. Certainly an improvement though!
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So these close-ups were taken of a C1 eh? @Wilch
I’m not seeing any issues whatsoever with the RGB subpixels as I had observed in @BendBombBoom’s pics. I’m not trying to be an OLED advocate or anything. Just after the truth. But based on this latest example I think WRGB OLED is looking a bit better still.
@Wilch , if you’re getting washed out colours due to the WOLED, can’t you simply bump the saturation in the Shader or the Colour on your TV until it looks correct?
That is exactly what white subpixels do, unfortunately.
@Cyber I agree that it’s passable but if you want to be a cork-sniffer about it (which I do!), if you zoom in you can see that it goes red-orange-yellow-green-cyan-blue.
The wash-out is probably the bigger issue, though.
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Brilliant - we’re progressing - sorry you had to reset your TV 
- its all for the best though 
. Yes chroma compression is a real problem with this shader (but generally it is too - we live with it for faster frame rates etc).
Right now why is it washed out - I did notice this with @BendBombBoom’s pics. Again flicking between SDR and HDR doesn’t help does it?
Maybe its time to start fiddling with the Gamma, Brightness, Contrast, Saturation settings in the shader parameters - see if they help at all?
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Just wanted to say this shader runs much, MUCH better now for me. Gone is the crippling performance regression. Still a shame I can’t practically use it at 4K at the moment due to not being able to run it at 60Hz, but I tried it anyway at 30Hz for giggles just to see how it looks.
Unfortunately, my TV appears to have the same issues @DevonCM reports. On certain mask and TVL settings, I get weird bright patterns stretching into the letter-boxed parts of the image. Particularly bad are the high TVL shadow mask presets. The only presets that are spared out of the box are the Sony PVM 1910 and Toshiba Microfilter presets, and you’ll notice those are relatively low TVL.
Then again, I also noticed the effect is lessened or even eliminated whenever I pull up certain menus on my TV’s Settings, which cover the whole left side of the screen, which is really strange. Perhaps a border would fix these discrepancies?
By the way, how would I go about editing the shader to add a cyan-magenta-yellow mask? It’s what I use with Guest-Advanced, since I output at 1080p and the TV’s scaler does the rest, and it looks remarkably good, but seeing as this shader is likely faster, I’d like to see if I could perhaps employ something similar here to ease the burden a bit on my potato-tier iGPU.
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Possibly before making such comments it might help if you used this shader? 
A list of all the presets in GitHub - find them all in the /hdr folder - download via RA’s online updater.
Great stuff glad youre seeing improvements! Have you tried using the SDR versions of the presets - they’re slightly cheaper than the HDR ones - let me know how you get on performance wise.
This patterning is strange - you’ve definitely got any sharpness settings at neutral - either 0 or 50?
If you want to add that mask just go into crt-sony-megatron.slang and edit line 211. Make sure to use 4K and 600TVL (which are the default settings for 2730QM preset).
EDIT: @GPDP1 I’ve had an epiphany I think I know why yours has patterning: are you upscaling a 1080p output display on a 4K screen by chance? If so that’s your problem unless your TV has integer scaling. Some OLEDs do I know. Is that happening? What screen are you using?
It’s an LG 4K TV with a VA panel and BGR subpixel structure. I do indeed normally output at 1080p, since that’s the only way I can get 60Hz output due to my integrated graphics (Intel HD 630) not being capable of doing better, to my knowledge, but I can still set it to output at native 4K if I so wish. At 1080p I don’t have this issue, although there’s another problem where the colors get distorted if there’s a lot of black area, but that’s completely unrelated to this shader.
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Why would you say this? What comments specifically are you referring to?
Did you understand this statement properly? I did try the shader.
I even asked for assistance in installing it.
You lost me on that statement there, am I doing something wrong by commenting?
In addition to that my 4K LG TV can only do 4K60p at 4:2:0. So I’m not sure if I will be able to get things to look like in your pics. Feel free to correct me if I’m wrong.
Using the 240p test suite I notice the “buzzing” on mixed or near white screens the most. Cycling through pure RGB screens I don’t see it. (My 90a is in game mode and the other modes don’t change the buzzing.) Here is an image of a pure blue screen. There is a lot red activation making it look more purple. Is it supposed to be that way?
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