Fantastic write up - really interesting stuff! Almost makes me want to update to Windows 11! (I really should anyway I know).
With regards to the overlapping phosphors: thatll just be a bug in the shader which should be easy to fix. When I get the time Ill look into it.
Yeah itll probably be the high resolution of that content. First thing to try is integer scaling. PSX I think is 240p so that really shpuld work without banding/problems so maybe something else is going on there.
What resolution is your tablet? What model is your tablet?
It is indeed, for the most part, but most of the cores support increasing the internal res, which frequently wreaks havoc with CRT effects.
Thanks! You should really update, as Windows 11 has many improvements in handling HDR signals.
It would be really awesome, if you could fix the overlapping phosphor issue. In the close up picture I posted, you can see, that the blue overlaps the green by one single row:
So the blue has to be moved 1 pixel row to the right (this is with the Display resolution in Megatron set to 8K and resolution set to 800 TVL).
The 4K / 300 TVL setting is just too coarse in my eyes, as the overall picture looks too “rough”. Maybe, for the sake of convenience, you could also just include a 400 TVL setting, as many may not know they can set the Display resolution to 8K in the shader with a 4K display.
I would be also interested about what you think how the Display resolution set to 8K and 800 TVL looks to your eyes on your Display’s. For me this combination is absolutely on point in regards to how the phosphors and scanlines look. Not too coarse and also not too fine like a Sony BVM / PVM, just spot on for me.
It would be awesome if @MajorPainTheCactus could do that and have RGB “magically” work on a non RGB layout screen but I don’t think that’s what’s going on there. It’s a case of incorrect layout being used for the layout of the panel which is something that has been tried, tested and proven already using empirical data.
If you switch your layout to RWBG there shouldn’t be any overlapping of a single blue subpixel unless there’s a bug that’s being manifested there.
You said there are no issues with the Aperture Grille at 300TVL using RGB Subpixel Layout but there are glaring issues to me. The spacing is incorrect and uneven. The Red, Green and Blue “phosphors” should be evenly spaced but they’re not. There are 2 subpixel columns of red, then 1 column of black, then 2 columns of green, then 2 columns of blue, then 1 column of black.
If you had taken pictures of the RWBG Subpixel Layout you would have seen 2 columns of blue, 2 columns of green, 2 columns of red, then 1 column of black.
You can see the correct layout of subpixels here:
It’s the red subpixel followed by the white subpixel, followed by the blue subpixel, followed by the green subpixel. The white subpixel is always off so that gives us our black gap after the red subpixel/“phosphor”.
This is why the even grouping starts at the blue, then green, then red then black gap in the Aperture Grille mask.
If you look at the photos in the links below you will see examples of both LED and OLED displays producing proper, evenly spaced aperture grille and slot mask “phosphors”.
What you are seeing there using that RGB Layout, even with the Virtua Fighter preset is far from what has already been achieved using LG OLED TV and many LED displays - which is the standard.
This Slot Mask doesn’t have the same issues of overlapping subpixels and the same uneven spacing as the RGB Virtua Fighter photo you shared. It uses the RWBG layout. The major issue with it is that when Deconvergence is used, the scanlines get messed up.
It might look even better as in more evenly aligned if it followed the Aperture Grille RWGB subpixel order of B, G, R, X. Or at least that’s how the Aperture Grille appears to be ordered but it could just be looking that way due to where the black gap (caused by the white subpixel being off) falls. So even if technically it starts at R and is RRXXBBGG to our eyes it’s going to look like groups of BGR because our eyes are looking for the evenly spaced and grouped triads regardless of what’s going on under the hood.
This is the empirical evidence that I’m talking about:
These photos of an acceptable looking aperture grille using RGB Mask Layout might be a little deceiving, not intentionally though. There is still the evidence of the large gap between the red and the green phosphor as well as the extreme closeness and almost overlapping of the green and the blue phosphors.
Again I say though, if @MajorPainTheCactus can pull off that perfectly aligned RGB Slot Mask on LG OLED TVs by shifting the blue subpixel by one subpixel I would be a very happy camper.
Unfortunately he has to work with what the display provides him and I don’t see the subpixels wanting to move to accommodate our desire so we have to work within and around their structure in order to get as close as possible to our desired result.
Feel free to take a look at this post. It shows how you can edit the Subpixel Layouts so you could experiment on your own if you wished.
I understand some people are adamant about perfect spacing, but in my experience having the colors in the wrong order is way more egregious than the spacing being slightly off. Certainly at a playable distance, but also on close inspection. Though I haven’t done the comparison at every single mask size. (Using the 27GR95QE)
So yeah it would be nice if there were more options for shifting pixels and spacing between phosphors without having to resort to blatantly wrong color order. Not just for Megatron but in general.
I don’t know if anyone else has done this yet or is bold enough to try it but if you take one of those LG WRGB/W-OLED TVs and rotate it 180° and then used the RWGB (OLED) Subpixel Layout, you should be able to get the “perfect” RGB Subpixel display.
Couldn’t you rotate one of the photos of the mask? As a test at least
Sure, no problem.
LG 55OLEDE6P 300TVL, Aperture Grille Mask, RWGB (OLED) Subpixel Layout (Rotated 180°)
LG WRGB/W-OLED Subpixel Layout (Rotated 180°)
Not sure what sub pixel layout your tv is but try changing cyan to yellow (or magenta) in one of the lines 427-429 ie out of the middle two colours the right hand one. Here: https://github.com/libretro/slang-shaders/blob/master/hdr/shaders/crt-sony-megatron.slang#L427 I will look at this properly but in the meantime this should be where the issue lies.
Thank you for the advice, I tried all combinations, but the changing (I tried all possible variations) only alters the hue of the colors. It does not move the two blue rows one pixel to the right, to eliminate the overlapping.
I only know, that after the three (red, green and blue) rows, there is a black row at the end. Maybe the space is just too tight for this specific 8K/ 800 TVL layout. I mean, maybe the single pixel black line / row after RGB can be replaced by blue, so there is enough space to eliminate the overlapping of green and blue.
It’s a bit hard to describe, but I hope you know what I mean 
And by the way, I am about to order a Notebook panel controller board and two of the finest Notebook displays available on the market.
One OLED 15.6 inch panel with 440 nits of full field white brightness (HDR around 600 nits) and a 15.6 inch Mini-LED LCD panel with around 1000 nits of brightness too.
Both 3840x2160 resolution:
With the controller board it is possible to power the displays without a Notebook. And these two displays should be the best on the market at the moment with OLED and LCD Mini-LED technology.
I am very curious how nice the shader will look on these small displays in comparison to my big 55 inch OLED TV. I guess it will be very hard to see individual subpixels, as the PPI is very high.
And another good thing is, that the bare Notebook displays / panels are not that expensive. The OLED panel costs around 200 euros, the Mini-LED LCD panel around 120 euros and the controller board around 60 euros.
I am also very curious which panel will look better, the very high brightness Mini-LED LCD panel with RGB subpixel structure or the medium high brightness OLED panel with this rather “weird” subpixel structure:
I keep you updated and will make some pictures, as soon as I received everything (everything comes from china, so will take a few weeks) and got the displays running properly, which I hope will work without any hassle.
Pardon if this came up before, I just tried the reshade port, on the the github it says that the neutral settings are based on the Sony PVM 2730QM. However the results are very different for me. Because I used a 1200p monitor for testing, I used the 1080p (and SDR) setting in Megatron for these shots. GPU is Nivida (also tested on Surface laptop with Intel - also looks odd there). Example in Retroarch:
Via Reshade:
480p, in Reshade I had to set height to 600 in my case (because I’m integer scaling x2). There are also JPG artifacts here I suppose, I nabbed the shot some time ago from the web.
Can you add 2560 x 1440p resolution for your shaders? I love them, and I would like to be able to enjoy them in the best possible way.
Apologies for the late reply, hmm this difference might be due to the reshade port being slightly out of date. Do you want the reshade to look like the retroarch version or vice versa?
Hi so although the shader parameters let you select 1080p, 4K etc it doesn’t mean you’re not able to get the very best experience for your monitor/resolution. All really these settings are doing is selecting the best CRT mask for your resolution to emulate slot mask/aperture grille/shadow mask. Those masks are really mostly the same thing.
For your resolution to get a perfect slot mask or aperture grille emulation you need 4 pixels for the mask (the default mask for 4K and 600TVL). Therefore the maximum CRT resolution you can emulate is 1440p / 4 pixels = 360TVL. Thats basically quite low to mid level CRT from the 80’s. 600TVL is towards the high end for the 1980’s.
There is a two pixel mask that is also widely used and that will get you a 720TVL image. You can get this by going to 1080p and selecting 600TVL.
Hi @Dennis1 it really does sound like there’s a bug in one of my masks for the type of display you’re selecting/using. I will take a look at this when I get the chance and see if I can spot it. When you’ve been playing around with the mask did you see any changes? Just asking to make sure you’re editing the right mask obviously.
Do keep me updated on your notebook display this sounds really interesting - I will say that layout doesn’t fill me with a lot of confidence but then I use my phone’s AMOLED display and its got a really strange sub pixel layout but you can’t tell because its so dense and impossible to distinguish with my eyesight at least (I dont need reading glasses at least)
Thank you very much! I’m going to try these settings ^^
No, the only changes are, that the colors change. There is no movement of the “phosphor” rows. I tried all combinations, but no success.
Both panels and the controller are on the way and should arrive within next two weeks. I have the feeling, that the Mini-LED panel will throw out the better picture, as it should be much brighter than the OLED panel. The contrast or black level advantage of the OLED panel might not be important here, as Mini-LED panels have many individual LED’s to deliver also high contrast levels and keep blooming or halo effects under control. For games I think this is less important anyway in comparison to watching movies which generally have more dark scenes. Also Mini-LED panels have the advantage of a RGB subpixel layout, like your Eve Spectrum Monitor.
But as you mentioned, it is almost impossible to see any differences as the “phosphors” are just too tiny, so despite the brightness advantage of the Mini-LED panel they should look pretty identical.
Before I ordered both panels I looked out for Notebooks and Monitors with Mini-LED panels and they are very expensive, below 1000 euros there is not a lot you can buy, especially with 4K resolution which is mandatory for good looking masks. So for around 120,- euros for the Mini-LED panel plus controller board it could be an absolute bargain if everything works. It does not have a case though, as it is just the pure panel, but there are also solutions for this, for example taking an old 15,6 inch PC monitor and swapping out the internals.
Building compact Arcade cabinets with Mini-LED panels is also an idea I have in my mind, as you can get pretty close to CRT quality with such good shaders like Megatron. In my opinion much better than those cabinets which just use cheap standard LCD panels and raw pixels without shader.
