Thats all I could make of CyberLab Megatron 4K HDR.slangp on my cheap 4k hdr TV.
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I find these look brilliant! Why don’t you try the SNES preset since its a SNES Game you’re playing?
How do they look in person?
Also did you set your Paperwhite and Peak Luminance values according to the Sony Megatron Color Video Monitor guidelines?
Lastly, don’t feel shy to share the make and model of your TV.
The more information we have as to how the shader behaves on different model TVs the easier it will be for those who come after possibly with similar models.
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I did those screenshots with it.
My TV very cheap and only 300 Peak Luminance.
Too dark and too heavy scanlines and mask for my taste, maybe its only because of my TV.
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Its POLARLINE 43PU11TC-SM 43" 4K UHD - cheap chineese model.
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You can still play around with the Paperwhite and Peak Luminance values. You could try to push the Paperwhite even higher and see if it looks better.
You can also lower the Gamma setting or set it to default.
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Subpixel Accuracy!
Potential Spoiler Alert
Can Mask Accurate be as Colour Accurate as Colour Accurate and supersede it?
On a real CRT aren’t we always in Mask Accurate mode?
Is it that we can’t mix the Mask Accurate Primaries to achieve all the possible combinations of colour required to be Colour Accurate?
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Does anyone have a video link to show how this Megatron’s shader works? Any step by step?
It always looks darker to me than conventional shader presets. 
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The instructions are in the first post and in the shader presets themselves in Shader Parameters.
You really need to set your Peak Luminance and Paperwhite values correctly for your screen.
It’s recommended to get the Peak Luminance from RTINGS or some other review site or from the manufacturer.
The Paperwhite is whatever looks good to you.
If you want assistance you might need to provide some more information, for example, what’s the make and model of your display?
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These look great! Maybe slightly oversaturated but maybe thats because of your tv - dont know.
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Sadly itll probably be because of your TV - at 300 nits its simply not bright enough for an accurate crt simulation (unless the crt was really quite dark that you were trying to simulate I suppose).
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You really need to use colour accurate for a TV that supports (some of) the wider colour gamut of rec.2020. The reason for this is that the sub pixel elements in oled/lcd are fundamentally a different colour and so you need to turn on different sub pixels to get the proper rec. 601/709 colour. As in the straight line from white point to peak green on a rec. 2020 set does not go through peak green on a rec. 601/709. This is also true if sdr tv sets that support wider colour gamuts just to a lesser extent.
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300 nits is ok for high TVL aperture/shadow mask , and that’s it imho (with Megatron).
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Finally got around to testing this and I can reproduce it. Hmm not sure whats going on here. It only appears to happen in hdr but Im not 100% sure of that as Im just eyeballing it. Certainly the shader in hdr mode definitely lightens the darks too much. The hdr shader that I built into RetroArch doesnt seem to suffer from the same issue. Could you confirm that for me i.e turn off video shaders and turn on hdr in the menu options. Youll need to set up your paper white and peak settings in the RA HDR menu rarher than the shader parameters.
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Yes it will do because its using 100% masks which is a more accurate simulation of a CRT. You need a bright display (500+ nits - the more the better) to make up for that. This is in essence what this shader is all about.
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Yes its a good point - the finer masks turn on more sub pixels and so youll get a brighter image. But what is an accurate simulation of a specific TVL for your resolution is another question.
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I can confirm that RA HDR with the equivalent settings does not cause this issue to occur.
I also recalled another good test case for this bug: in Donkey Kong Country, the “© 1994 Nintendo” during the intro has intense artifacting/boosted brightness in the darker colors surrounding the text with 4.2+.
As an aside, this also reminded me that i wanted to verify something: “Expand Gamut” in RA and “HDR: Original/Vivid” are the same setting, correct?
Does On/Vivid inaccurately juice/enhance/oversaturate colors for additional pop, or does Off/Original prevent the output from exceeding rec709 color gamut?
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Yes expand gamut and original/vivid are the same thing. Its there because the inverse tonemap I employ can slightly desaturate the image and this brings it back up. Having it off is probably more accurate - its a bit like the ‘dynamic mode’ on your hdr tv vs film maker mode. I havent got an image of the colour space but its a microsoft transform and theyve published it on github which is where I got it from.
So my gut feeling is that the tonemap is being applied twice by a bug in RA but Im going to have to test that. Bear with me a moment.
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Here, Samsung Q70A 4K 60-120Hz
OK, Here is a link:
I understand I need to adjust something on the TV. Do I need to activate HDR in Retroarch? Does the TV need to be in gamer mode?
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That was my expectation once i realized they were the same setting, ty.
For the record, i think the setting description for “Expand Gamut” (and possibly even the setting name) could stand to be clarified to make it clearer that is what the setting is doing.
Anecdotally, before i knew they were the same setting, based solely on the names and descriptions, my first brush response was that “Expand Gamut” should be on (to allow for colors outside rec709/sRGB) and “HDR: Original/Vivid” should be Original (for more accurate colors).
One of those?
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I’ve seen this issue in a few games too, seems like very dark - but not quite black - areas are light grey. You can see it at the start of primordia (scummvm) and in the bar in monkey Island 2 (dos/Amiga/scvm)
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