Set the max luminance to what your TV is capable of. One source of this information is RTINGS reviews of the set.
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@Wilch Yup as Cyber says here. Once you do that you may need to play around with paper white nits. Paper white nits is what you expect a sheet of white paper to be (not that bright!). Usually this should be set to around 150nits BUT when dealing with these CRT shaders that have hardly any sub pixels turned on compared to normal then you can just whack paper white nits up to the same as max nits and that’ll give you the brightest experience. Depending on your TV though that maybe too bright. Have a play around.
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I thought it looked pretty nice after making some adjustments for the low-res SDR displays I used. I also had a brief look at the shader presets on a 4K TV, but any feedback will come later when I’m able to do some more thorough testing. That being said, if the Toshiba preset is essentially another VGA monitor variant, I was wondering if your project actually benefits from photos at different resolutions? There’s already quite a difference between 50 and 60 Hz modes on regular SD (15 Khz) displays.
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Hello Friends,
I stumbled upon this thread as I was looking into retroarch and HDR.
I read this thread but I still have a question (which i believe was asked earlier but without answer)
I apologise in advance if I missed the information I am looking for.
I have a LG CX Oled TV and retroarch is running on a windows 10 pc with a RTX 3070 card.
Cable is hdmi 2.1 and I run my desktop at 4k 120hz color bitdepth being left to auto (if that is important)
The TV input is set to PC and picture to Game mode.
Automatic Tone Mapping is disabled.
I am confused about the HDR settings to use with this shader and the presets.
Basicaly what I do is that I turned HDR on into RA with max luninance at 600 Nits and PaperWhite at 200.
When I enter RA the screen switches to HDR indicating that it is working.
The strange thing is that when i apply any preset for the shader (for instance one of the PVMs) the image will appear washed out and if i move the max lum and Paper white settings in the shader menu it will not change much to the washed out aspect of the picture)
So I am wondering if I am maybe doing something wrong.
Could anyone please advise ?
I am also trying to understand if the shader’s HDR settings will override RA’s setting.
I would also like to know if HDR should be turned on in Windows directly.
And lastly if here is anything that should be noted for the use of the shader on an LG Oled screen.
Thank you 
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It’s been mentioned several times, but the Megatron shader will only work as intended if using a display with a regular RGB subpixel layout, which OLED sadly lacks. The Megatron requires a very particular setup to work properly.
You can still use it, but you won’t get results that look like the amazing photos posted by @MajorPainTheCactus.
@guest.r’s excellent shader is a great option for OLED users and those with weird subpixels.
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As mentioned here the same RRGGBBX mask that seems to work well with OLED TVs when Layout is reversed is available in Sony Megatron Color Video Monitor.
Once the option to flip the layout works properly for that mask in Sony Megatron Color Video Monitor I don’t see why OLED TV users shouldn’t have a wonderful experience down to the phosphor level as well.
I haven’t tested it yet but hopefully I should soon.
Use RRGGBBX mask with reversed Layout for OLED in either Sony Megatron Color Video Monitor or CRT-Guest-Advanced if you want your “phosphor” triads to look even and properly aligned.
Other modes will look good as well but the “phosphor” triads wouldn’t look as they should.
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thank you both for taking the time to answer.
i am still confused as the megatron appears to display good colors etc sometimes when i switch hdr on/off in RA.
Cyber,
i looked for the RRGGBBX mask in crt guest advanced but could not find anything (may not be looking at the correct place)
I have the choice for crt mask between 0 cgwg up to 7 trinitron.
english not being my primary language i may have missed part of the discussion especialy in the guest thread.
as such i truly apologise for asking so many potentialy obvious questions.
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It’s Mask 12. You have to set the Size to 1 as well and change the Layout from 0 to 1 .
If you don’t have a Mask 12, then you probably need to head over to the thread and get the latest update.
Both CRT-guest-advance and Sony Megatron Color Video Monitor still look pretty good despite the strange OLED subpixel layout even without using RRGGBBX Mask with reversed Layout. The OLED subpixels seem to line up more or less as they should or at least much better using RRGGBBX Mask and reversed layout though.
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indeed the shader was not the latest in RA.
I downloaded it from the thread and i can now see what you mean.
small question does guest work with hdr ?
as for megatron i will wait for the shader to develop further but it is already great
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Guest does not work with HDR but traditional methods are used to simulate the same look.
The Megatron was designed to use the brightness of the display to mitigate the traditional methods.
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Thank you for the clarification.
I had a run with Megatron using one of the PVM settings.
I must confess that I didn’t notice the text within the shader that explained that max lum and paper white settings from the shader would override RA before asking my initial question.
Anyway keeping max lum and paper at 700 plus inverted RGB gave the best result.
I had to restart RA for the effect to apply.
I noticed that whites were a bit overblown in Capcom games so i changed the gamma value to 2.4 as input and that helped.
I own several BVMs (20E and F series) I will compare the output of my OLED to one of them to get an idea how close / far I may be from such monitors (of course this is not apple to apple comparison)
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Hi Miaou! Sorry for the delayed response, I’m a bit busy at the moment but aren’t we all! 
So in answer to your question the Sony Megatron is a true HDR shader (in that it uses HDR buffers and swapchain) and as such will override the settings in RA.
You need to definitely enable HDR in Windows that’s a must. As for why it looks washed out - that is almost certainly because HDR is not on somewhere - check the shader settings and make sure it’s set to HDR and then work back up the chain from there - RA next, Windows after that, your gfx card, then your cable and then your display. Phew!
This shader should look alright on an OLED, it’s not perfect because of the extra white sub pixel but that only gets turned in very bright areas. Its mostly alright though - much more important is that you don’t have any kind of sharpening on.
Anyway let me know how you get on.
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Yes you’re right you won’t get a perfect image but I think it’s wrong to say that guest’s shader or any other for that matter will resolve that issue - we can’t remove those extra sub pixels as you know.
What guests is better at doing is supporting low brightness screens (at the expense of CRT accuracy) - you might put OLEDs in that low brightness bracket but I’ve seen reasonable results.
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Hopefully we can get to the bottom of your washed out colours - it’s definitely a HDR setting not quite set correctly. HDR is currently a bit of a pain not being the default and having to be switched on in a whole slew of places.
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Yes to all you said but just to add that although it’s not a native HDR shader Guest does work with the RA built in HDR shaders I made i.e just turning on HDR in RA.
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Your problem will be brightness when trying to match those PVMs/BVMs - the later models are incredibly bright allowing them to have much narrower scanlines which helps with motion blur.
Are you still getting your discoloration?
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Hello MajorPainTheCactus
Apologies for the late answer, I was also busy here…
So turning on HDR in windows appears to mess things up and I am not sure why.
As reported in an ealier post what appears to work for me is to leave HDR off in windows but activated in RA.
I noticed that when HDR was on in windows and RA launched it would deactivate HDR in windows but keep some kind of HDR applied (if i tried to summarize it would be that the picture I get is SDR within an HDR container) I am not sure if this is a bug in windows or some other conflict.
So if I leave HDR off in Windows when I launch RA the HDR icon will pop up on my screen indicating that I switched from SDR.
When i enter a game the colors are good now (i use aperture and 1000 tv lines as i love the very sharp look of BVM screens) the only small adjustment that needs to be performed then is on the gamma side.
I set input level to 2.30 as I feel the overall contrast of the picture is better on my screen.
I am plugging my neo geo (RGB bypassed) into one of my BVM as we speak as I was using games like Pulstar, Real Bout or Metal Slug to compare, I may also try Mister or Retroarch through CRT Switchres to run Capcom games.
I know it will not be an exact comparison due to the different nature of the screens but i just want to get an idea.
Quickly editing upon results:
So no results are not good, for some reason whites are burned when using HDR.
One example is the beach arena is Real Bout Special the fine details in the bright area of the beach are lost when running RA in HDR while they are properly nuanced on the BVM either running the original hardware, mister or RA using CRTswitchres.
Switching to a SDR shader fixes this this as well.
I have to go for today but i will test again
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So if you don’t switch on HDR in Windows you aren’t using HDR. You must switch over to HDR in the Windows itself and then switch on HDR in RA and then use a HDR preset for the Megatron.
First ignore the Megatron and just get HDR working in both Windows and RA. The colours should not be washed out and you should see the white text in the menu ‘glow’ and the colours should be ‘vivid’ in game. Play around with the HDR settings in RA at this point to get things looking right for your display.
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When using vulkan in RA I don’t need to enable hdr in windows, but if using dx I must enable hdr first. This is on win10
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I confirm what Wilch stated,
Once RA opens the HDR logo pops up evidencing the fact that the display switched from SDR.
Triggering HDR from the windows settings does not solve the loss of details in the bright parts of the screen.
I tried to reduce Paper White as I thought it was linked to this but the result is that the screen looses brightness but does not restore the overly bright parts of the screen.
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