Advice on Mega Bezel HDR Megatron shaders at 1440p

[srchrono]

Hi all,

I recently upgraded my monitor to a Gigabyte MO27Q28G 1440p tandem WOLED and I am trying to get the Mega Bezel Megatron shaders to look good. I know the HDR shaders are primarily aimed at 4k monitors, but I have successfully gotten really punchy, nice looking colors and brightness out of the monitor using the Mega Bezel HDR presets. The main issue is that I can’t get the mask to show up very well, so the pixels don’t look very sharp. These are the settings I have been playing around with:

SDR|HDR: HDR

Mask Accurate/Color Accurate: Color Accurate

Display Color Gamut: DCI-P3

HDR: Display’s Peak Luminance: 1500 (advertised peak nits, not sure if actual)

HDR: Display’s Paper White Luminance: 500

HDR: Original/Vivid: Vivid

Display Resolution: 1080p

Display Subpixel Layout: RWBG

Screen Type: Slot mask

Resolution: 800TVL

If I set the resolution to anything less than 800TVL, the mask is so strong the light and color can’t penetrate it. If I set it to 800TVL or higher, the mask gets too faint. I’m coming from mega bezel shaders that are based on crt-guest, where mask strength and scanline size were separate parameters, so I’m trying to understand the Megatron equivalent. Is it really completely controlled by just the mask type and the TVL (and maybe paper white)? I have been playing around with the red, green, blue Megatron scanline options (mix, max, attack, etc.), but they don’t seem to adjust the picture in a way where I can make sense of how to use them (if that’s the solution). Any guidance on the mask-vs-brightness relationship at 1440p would be much appreciated!

Also, happy to share more details about my setup if needed. Thank you!

[srchrono]

For others interested, after digging around in the forum threads a bit, it looks like CyberLabs recommended to make Display Resolution 4k and TVL be 800. I’m happy to report that did give an effective mask. Now I am trying to dial in the right values to get a good balance between brightness and color. I’ll follow up with my settings once I get it figured out.

[Telmo]

So your monitor is 1440p but you are using a 4K resolution?

[Cyber]

There are no 4K or 1440p or 1080p CRT Shaders. Those are just labels which attempt to simplify attaining a particular emulated CRT TVL. So the actual “label” chosen doesn’t matter. All that matters is getting a mask and TVL that looks well and consistent at whatever resolution your display is capable of.

@srchrono According to this article: https://tftcentral.co.uk/news/gigabyte-announce-mo27q28g-with-a-27-primary-rgb-tandem-woled-panel

…your display has an RGWB subpixel layout but you’re using the RWBG/WOLED subpixel layout in the shader.

This new display panel subpixel layout hasn’t been tried and tested but you can probably start with the RGB setting and see how it looks.

I have some tests I’ve developed to see how the new tandem WOLED layout is rendering the traditionally used CRT Shader Subpixel Layouts. Let me know if you’re interested in doing some testing.

Your questions are very valid though. Sony Megatron is uncompromising when it comes to mask strength and scanline strength but you can adjust how thick or thin the scanlines are as well as other dynamics which can affect the brightness of the image.

Also, the higher the TVL you try to emulate, the less black or dark subpixels would be on the screen and so the higher the brightness as well.

You can try shaping your scanlines in a way that the gaps are very large in the dark areas, thus conserving power limit for the brighter areas where the gaps can be more on the thinner side. Thicker scanlines in the bright areas and thinner scanline gaps in the bright areas, lead to a brighter overall image, while the thinner scanlines and larger gaps in the darker areas help improve the overall contrast and sharpness.

You can feel free to post some photos of the screen so that we can better visualize the issues you’re having.

Here’s an example of a 1440p user’s experience with Sony Megatron Colour Video Monitor:

CyberLab Death To Pixels Shader Preset Packs

Here’s an example of my setup when it comes to scaling and latency. I intend to publish these so that users can have as great of an experience as I do. If not using VRR then Set Automatic Frame Delay to On. [RetroArch Screenshot 2025.10.12 - 02.48.07.61] [RetroArch Screenshot 2025.10.12 - 02.48.20.56] [RetroArch Screenshot 2025.10.12 - 02.48.43.59] [RetroArch Screenshot 2025.10.12 - 02.48.56.25] [RetroArch Screenshot 2025.10.12 - 02.49.27.57] PSA for 1440p Users: From the user pagge from Di…

This is the test material which you can perform if you want to contribute to finding out which Subpixel Layouts work best with the new Tandem OLED BRWG panels:

CyberLab Death To Pixels Shader Preset Packs

Did you follow the instructions? That question would be best answered by @Guest.r. I did ask him about this already though and he advised me that the existing layouts should be tested with the new displays first. So here we are. I do have presets that can be used on DreamCast games using CRT-Guest-Advanced. They’re in my Mega Bezel preset pack. I also have many other presets which I made for DreamCast using other Shaders, including Sony Megatron Colour Video Monitor. They go by the Turbo …

Actual Subpixel Layout - RGB, RBG, BGR

Subpixel Layout in Shader Parameters:

CRT Guest Advanced - Mask 6

Sony Megatron Colour Video Monitor - Display’s Resolution 4K, CRT Resolution 800TVL

Actual Subpixel Layout - RGBX, RBGX, BGRX

Subpixel Layout in Shader Parameters:

CRT Guest Advanced - Mask 10

Sony Megatron Colour Video Monitor - Display’s Resolution 1080p, CRT Resolution 300TVL; Display’s Resolution 4K, CRT Resolution 600TVL

Actual Subpixel Layout - RRGGBBX, RRBBGGX, BBGGRRX

Subpixel Layout in Shader Parameters:

CRT Guest Advanced - Mask 12

Sony Megatron Colour Video Monitor - Display’s Resolution 4K, CRT Resolution 300TVL

New CRT shader from Guest + CRT Guest Advanced updates

What mask and mask size settings would give me RGB/BGR triads on a 1440p display? For example I know Mask 6, size 1 is ideal for 1080p. Mask 12, size 1 for 4K. What about 1440p?

New CRT shader from Guest + CRT Guest Advanced updates

The only masks that don’t result in clean triads of some kind are masks 1, 3, 4, 7, 8, and 11. Masks 2 and 6 are identical in layout, and so are masks 0 and 5 for that matter. What TVL count are you shooting for? For instance, Mask 6 size 1 at 1080p results in 360 TVL (preferably using the subpixel arrangement opposite that of the panel’s to have cleanly spaced subpixels i.e. using BGR on an RGB panel). This is more or less how it boils down: 1080p Mask 0 = 540 TVL Mask 6 = 360 TVL Mask 10 = 2…

New CRT shader from Guest + CRT Guest Advanced updates

Thanks @GPDP1! I’m looking for around 300TVL to 360TVL. Your answer is exactly what I’m looking for. I can use this to start creating some 1440p Optimized versions of my recent presets without having to resort to using a 1440p screen. Thanks again @GPDP1. This is exactly which mask and size I’ve been using for my existing 1440p presets. I wasn’t able to see proper RGB triads when I was testing them a long time ago but then I was actually scaling the 1440p resolution to fill my 4K screen inste…

New CRT shader from Guest + CRT Guest Advanced updates

For a slot mask preset, you’ll probably want 4 wide, 2 tall for Mask 10 at 1440p.

New CRT shader from Guest + CRT Guest Advanced updates

Wow, I didn’t know that mask type and size were related to TVL simulation. I aim for 800TVL of the aperture grill like the Sony PVM series on my 4K/RGB array LCD monitor. Could you please let me know which one would be best in this case?

New CRT shader from Guest + CRT Guest Advanced updates

Closest to it would be Mask 6 using the BGR subpixel arrangement, or Mask 9.

New CRT shader from Guest + CRT Guest Advanced updates

I have a 1440p monitor and I use mask 10, slot mask width 4, height 2: best option. You could use 11, which is brighter, but less “deep” (10 is RGB, 11 is cyan, magenta and green if I remember correctly). Edit: 10 is RGBX, 11 is red, yellow, cyan and blue.

New CRT shader from Guest + CRT Guest Advanced updates

Mask 11 ends up being the same TVL count as Mask 10, as it uses four pixels to make a complete phosphor triad (red and blue come together to form magenta). It’s a good mask to use if you don’t mind trading a bit of accuracy for twice the brightness output as Mask 10. I use it at 4K myself for N64 games and above.

Sony Megatron Colour Video Monitor

After reviewing your screenshots, everything looks as expected. 1080p 300TVL uses the R-G-B-X subpixel layout, which would probably look great at 1440p and 4K. 1080 600TVL uses Magenta-Green. 4K 800TVL uses R-G-B/B-G-R and that is great for 1080p.