Let's talk about the beam simulator, displays, etc

Nesguy · 8 August 2025 16:09

Hey everyone, long time no see, glad to see some of the regulars still here.

This beam simulator thing is very exciting stuff! It also looks like I probably won’t be able to afford it for 10 years 240Hz? Yikes! What kind of graphics card are we going to need?

Do we even have displays for this?

I’m assuming we still want HDR1000 for 100% masks. Are there any displays that are 4K, 240Hz, HDR1000, and 27"?

Looking at some currently available options…

Tempest GP27U MiniLED - except this one tops out at 160Hz
AOC AGON AG274QZM - except this one tops out at 1440p 
ASUS ROG Swift PG32UQX - except this one tops out at 144Hz
AOC - 27" Q27G40XMN - also 1440p

etc.

AOC U32G4ZMN - this one is really exciting, but hasn’t been released yet. A 31.5-inch 4K 240Hz QD-Mini LED, HDR1200? At a shut up and take my money price of $650? Keep an eye on this one!

There are several OLEDS that are 4K and 240Hz - but OLED only reaches HDR400. 100% masks need HDR1000 at a minimum.

Has anyone tested the beam simulator on one of these OLEDs, while using 100% masks?

It looks like right now the choice is between blur reduction with brightness compensations when using masks, or less blur reduction and 100% masks.

If you want to optimize blur reduction, then you’ll have to give up some CRT mask accuracy. If you want to optimize mask accuracy, you’ll have to sacrifice some blur reduction.

If you’re using an OLED, you probably don’t care as much about perfect CRT masks, since the subpixel structure of these displays makes it more difficult to emulate the masks perfectly.

It looks like high refresh MiniLEDs are on the horizon, so we won’t have to choose between blur reduction and mask accuracy for very long.

Looking forward to following this as it develops!

Cyber · 11 August 2025 21:24

Hmmm…

First I’d like to say a warm welcome back to one of the forefathers of accurate CRT emulation!

While you’re at it salivating at the thought of a 31.5" 4K , 240Hz HDR1200 display, don’t forget to check out the specs and prices on these behemoths!

The TCL QM851G is brighter but the QM6K sports an RGB Subpixel Layout!

Also the CRT Beam.Simulator seems to be producing mixed results, especially on LCD panels. I’m not sure if you’ve tried it before but there’s an option to protect LCD’s from image retention but that results in artifacts.

https://www.youtube.com/live/gMnXc3WfSWs?si=hzS87YTH25OKNgq5

Well this might be for monitors but TVs are now much brighter than that since last year’s LG G4 with MLA panel technology and this year’s G5 with the new 4Stack RGB Tandem OLED subpixel panel technology.

Also the latest, 4Stack RGB Tandem sports a new Subpixel Layout but there’s still a white subpixel in there.

LG also changed the subpixel layout. Instead of the RWBG layout they’ve been using since they first introduced their OLED panels, the G5 is different. It looks to be an RGBW layout, but the first subpixel is blue, so we’re classifying it as a BWRG layout. For a closer look at this new subpixel arrangement, we took a video.

The TCL QM751G Sports some insane brightness figures for the price. Easily competing with and even surpassing the brightest OLED TVs on the market for a fraction of the cost.

They were going for under US$480 last year for a 55" model.

The brightness is insane and a sight to behold. I wet my toes with BFI on one but every time I turned BFI off, my eyes preferred the extra brightness.

In addition to that, I’ve been experimenting with playing at reduced Integer Scales for example 8X and 6X for a really bright and dense look (at least in terms of the pixels and scanlines but at the expense of mask resolution though.

Lower integer scales, equal smaller window sizes and therefore higher peak and sustained brightness.

Anyway, I’ll leave you with a few pics of some of my latest presets in action on a TCL QM751G.

Nesguy · 12 August 2025 01:41

VESA has recently introduced the DisplayHDR True Black 1000 standard for newer OLEDs - very exciting! This could be game over for MiniLED - it’s a race now to see which tech can be made cheaper, faster.

The QM851G does not meet the HDR True Black 1000 certification, but it comes pretty darn close at 965cd/m2 for a sustained 100% window- very interesting! The subpixel layout is a drawback, though.

The QM8K reaches 667 cd/m2, so not enough for my purposes.

I haven’t used the beam simulator yet - my monitors only go up to 160Hz. It wasn’t something I was really factoring in at the time.

It looks like the OLED TVs mentioned don’t meet the True Black 1000 spec, which is what I’d be looking for in a new TV if I was planning on using 100% masks.

https://displayhdr.org/

https://www.tomshardware.com/monitors/vesa-reveals-new-performance-tiers-for-motion-clarity-and-hdr-quality-displayhdr-true-black-1000-and-clearmr-21000-certified-devices-to-start-arriving-early-next-year#:~:text=VESA%20reveals%20new%20performance%20tiers%20for%20motion,first%20500Hz%20OLED%20gaming%20monitor%20for%20$1%2C300.

If they can produce a True Black 1000 display with an RGB subpixel layout at the same price as MiniLED, that’s game over for MiniLED in the CRT emulation wars.

Another possibility is cheap 8K True Black 1000 displays - at 8K resolution, the subpixel layout isn’t really a concern anymore.

I hadn’t thought about the reduced scale trick - that’s an interesting workaround for those with larger displays that don’t mind the lost real estate.

Nice work on the presets! I spend very little time tweaking these days- it took about 5 minutes to make everything look “perfect” on an HDR1000 display using guest-dr-venom. Absolutely worth the investment.

Cyber · 12 August 2025 21:43

Thanks, everything you said before that is interesting as well.

If you look at this picture, you might notice that it uses a strange 4 colour RCYB mask, which was intended for 8K displays. While I liked the height of the slot mask compared to what was available under the 4K section, that was always unacceptable.

CyberLab Megatron miniLED 4K HDR Game BFI SNES S-Video Slot-Mask Sharp Advanced Neo-GX Super Fine CRT Shader Preset

I recently modified the Sony Megatron Colour Video Monitor Shader to change it into a standard RGB/RBG/BGR layout for 4K Displays.

I wasn’t sure how best to integrate it with the original Sony Megatron Colour Video Monitor or if I even wanted to so I just crested my own self contained mod which you can access if you download my latest CyberLab Megatron miniLED Epic Death To Pixels HDR Preset Pack.

It integrates, some important tools from the IMG Mod shader for cropping and centering, noise aka grain, corners, new Grade, CRT-Guest-Advanced-NTSC AfterGlow and Horizontal Filtering Section and XBR-LEVEL-2 shaders.

In its current state XBR messes with the grain/noise so you might have to use either sparingly to avoid unwanted artifacts.

I was at a point of almost complete satisfaction before when I set out to achieve a fine balance between smoothness and sharpness without using Super-XBR and that’s how my W2 (miniLED Wave 2) presets came about. I was happy that I was able to reduce the number of passes from 19 to 12 while achieving similar or better results.

Super-XBR has always been a bit flawed for my purposes so I was pleasantly surprised when I saw @guest.r showcasing some examples which used the XBR-LEVEL-2 vs Scale-FX and I knew immediately that it would be a perfect match.

These days, I’m mainly focusing on solving issues like Scanline/Mask alignment, especially when switching scale factors and using slot masks.

Many times it affects the centering of the horizontal slots and the vertical offset needs to be adjusted to address that.

Also certain scale factors work better with different Scanline dynamics setups or it could also be a core/vertical resolution thing so I tend to stick to Scale Factors which produce even scanlines.

I’ve all but given up on sharing “dark” screenshots because many folks still just don’t seem to get it.

So I really don’t know how many other folks get to enjoy the type of experience that I do.

I also use HDR virtually all the time in my Windows Setup and in RetroArch.

What TCL did last year was nothing short of amazing with the QM751G and QM851G, it’s too bad that they’ve also stepped back in some respects with the 2025 lineup, at least so far because they might be releasing a QM9K.

I doubt miniLED is dead because at least on the TV side of things, it seems like manufacturers make higher profit margins on high end miniLED than on OLED.

RGB-miniLED, more zones, better local dimming algorithms mean that what’s good now should be getting even better.

Then there’s the HDR Impact that currently only MiniLED can provide.

The QM8K has a new type of panel that both improves native contrast ratio and wide viewing angles, while giving us an almost unique for a VA panel, RGB Subpixel Layout.

Having the QM751G and experiencing the things that I mentioned about preferring higher brightness and smaller window sizes over BFI and better motion clarity makes me wonder what could be done with a QM851G instead.

It would be sad to see it drop off the market without an equal in brightness, affordability and lack of bugs/new artifacts, which seemed to have plagued the 2025 line’s launch. I see some of the weirdness sometimes where the algorithm just doesn’t know what to do or can’t make up its mind when I’m navigating RetroArch menus with a minimal amount of white text on the screen surrounding by alk of that grey.

The backlight starts to oscillate between light and dark because that’s what grey is, right but it’s the small amount of white text that throws it off sometimes.

Nesguy · 12 August 2025 17:54

I had the same idea once (I think I was calling it RGBX?) but because I’m lazy I just went with the RGB mask and doubled the phosphor width (because it’s easy to do in GDV) - it’s definitely more accurate to include that additional black pixel, though. Photo looks great! I think at 4K this is also a bit closer to that ~300TVL 90s consumer grade sweet spot.

Yep, screenshots are not representative of how these things look when running fullscreen- unfortunately, what grabs people’s attention are the flashy screenshots, but the same settings used to produce those screenshots are often not optimal IRL.

That’s good to hear, as I’ve been greatly enjoying my MiniLED monitors despite the drawbacks. The bloom problem seems to be mostly solved on the next generation of MiniLEDs, from what I’ve seen.

I don’t use the local dimming when using RetroArch because it causes significant dimming across the entire screen and I need all 1,000 nits for the slot mask

How well is beam simulator working on MiniLED vs OLED? Right now I’d say OLED has the edge just because that’s where you’re finding the fastest refresh rates- but MiniLED looks like it’s about to catch up in that regard.

Cyber · 12 August 2025 21:46

After a few attempts, I can’t seem to get it to function acceptably on my miniLED. For what it’s worth, I can’t get 4K 120Hz RGB 4:4:4 to work using my setup either which uses an old GTX 1070 and a Display Port 1.4 to HDMI 2.1 adapter. The TV supports it according to RTINGS though so it’s probably the Adapter and Graphics card combo that’s causing the limitation.

Due to this, I’m limited to using Dot Masks or some specific Mask Layouts which play nicely with RGB 4:2:2 Limited or have to play at 1080p with no scaling, which really isn’t feasible.

Maybe 1440p with no scaling, may not be so bad but I’d have to manually add that resolution.

Anyway the problem is when trying the CRT Beam Simulator, there’s always this horizontal hum bar going up the screen. I think it’s tied to the parameter to prevent image retention on LCD screens.

OLED displays don’t need to use that parameter so that’s a huge advantage right there as the parameter seems to always have a visible artifact.

The creators of the Beam Simulator also admit that it might be not play as nicely with HDR setups if I recall correctly.

In any case the built in BFi (Strobin) on my TV “just works” even at 60Hz desktop refresh rate, so I used to use that instead.

By the way, there are 2 CRT-Beam-Simulator shaders if I recall correctly. The one made by Blur Busters and then @kokoko3k made one recently which is supposed to have some improvements.

As a fun sidenote, I actually had that concept for a vertically scrolling horizontal beam to improve persistence motion blur a long time ago and @hunterk made the shader to test it but of course not much could have come out of it at only 60Hz, which was the refresh rate of my OLED TV and there was also no way to run shaders or shader based effects at more than the content’s refresh rate/fps.

Fast forward to now and we have Subframes which enable shaders to run at desktop refresh rate while content can run at its original framerate or a multiple of the desktop refresh rate.

Thanks

It’s supposed to as the preset was designed to match a real consumer grade CRT. (not sure if it’s ~300TVL but if you say that’s what it looks like then that’s what it looks like).

I think the real CRT had a higher TVL though, which is why I had to switch to the 4K Mask or higher TVL 8K Mask in order to more closely match it.

Real CRT

CyberLab Megatron miniLED 4K HDR Game BFI SNES S-Video Slot-Mask Sharp Advanced Pro Monitor Edition CRT Shader Preset

All those presets/derivatives receive a free upgrade if run on my modified Sony Megatron Colour Video Monitor shader where the 8K Display’s Subpixel Layout Parameter is really just a 4K_B.

Sony Megatron Colour Video Monitor also hides the Slot Mask Height adjustment from thr end user so thus is how I had to get that same TVL with the ideal height compared to the 4K version which features a taller phosphor height.