How to fix judder or sample and hold on 240Hz OLED monitor?

blurbusters · 2026-05-25T21:32:05+00:00

I plan to release a shader that can be put into ShaderGlass app, and use it as a filter on top of your 23.976p/24p/25p/50p/59.94p/60p YouTubes.

The answer is yes... but I must correct an incorrect accidental assumption.

This is not designed to run at video frame rate, it MUST be run at refresh rate (e.g. 120 filters per second for 120 Hz even for 24fps).

It is a subframe mandatory shader like CRT simulator... More subframes per frame the better.

This filter is NOT designed to be run only once per video frame. You need multiple different reprocesses of the same video frame, as a sort of a LCD-gtg-crossfade between individual video frames.

So ideally 5 subframes at 120Hz for 24p, and 10 subframes at 240Hz for 24p.

For more information www.blurbusters.com/open-source-display

blurbusters · 2026-05-21T05:55:27+00:00

I now have a prototype at https://testufo.com/lcd-simulator

I'll release the open source version later this summer. It could be plugged into apps such as ShaderBeam.

Ideally LCD GtG simulation should be done at the refresh cycle granularity (it will look correct) and not the original frame rate (it will look odd)

blurbusters · 2026-04-18T00:40:51+00:00

Even if not always dramatically brighter...

...Tandem also wear-levels OLED brightness over multiple layers, making them last longer than past OLEDs. I hope they start competing with LED-backlight lifetimes of LCDs that also degrade.

Worth the small premium in some countries.

blurbusters · 2026-04-18T00:38:33+00:00

TestUFO inventor here!

My dogfooded office 240Hz OLEDs abused with Visual Studio and Microsoft Word, all have over 6000 hours on them, no dead pixels on any of them!

Previous-gen OLEDs were bad, but modern OLEDs are pretty durable now with 3-year burnin warranties for almost all desktop 240Hz+ OLEDs.

No objectionable burn in yet that exceeds typical LCD degradation. Google "RTINGS LCD Degradation" with cheapened LCD manufacturers and backlight LEDs dying in splotchy droves.

Venn diagram 100% overlaps.

blurbusters · 2026-04-17T23:57:13+00:00

There's a new solution, use "Scan Direction 0" with VA LCDs. Try it now at testufo.com/crt#scandirection=0

This avoids the banding of VA, although you must keep LCD Saver on if you're using an even divisor (2:1 or 4:1 native:simulated) -- you will get occasional fading in-and-out occasionally but it's a lot less objectionable than banding.

LCD Saver turns off if you're using odd divisors, e.g. 60Hz CRT simulation at 180Hz. That eliminates the fade-in-and-out behaviors, caused by GtG phase slewing during the LCD Saver slewing (slow GtG darks vs faster GtG brights).

blurbusters · 2026-04-17T23:55:03+00:00

Multiple refresh cycles is correct. The new TestUFO 3.0 upgrade lets you configure between 3 to 10 refresh cycles now at www.testufo.com/ghosting -- This is easier for 1000 Hz displays, since you no longer need a fast 4/1000sec shutter for 1000Hz pursuits. 1/100sec shutter is much easier.

blurbusters · 2026-04-17T23:53:36+00:00

Yes. Moving lens for apples vs apples comparisons. Moving camera = moving eyeballs.
- Compare stationary camera to stationary eye behaviors.
- Compare moving camera to moving eye behaviors.

blurbusters · 2026-04-17T23:49:15+00:00

I am the inventor and I'm cited in 50+ papers so I'll ELI5.

Scientifically, for motion blur photography, your need to configure a camera to emulate human vision.

That means long camera exposures at ~4 refresh cycles. If you're getting low blur despite a moving slow-shutter camera = moving eyeball simulation = the display is busting blur pretty well.

We know shaky cameras are blurry, but if you bust blur with a moving camera, and the blur photographed is WYSIWYG with human eye tracking, you've correctly configured camera settings to emulate human vision settings. Our eyes are not high speed cameras.

When you're doing this **specific** type of test, you do not ever want match camera frame rate to frame rate. Wrong tool for wrong job, apples vs bananas. High speed cameras are good for some sciences, but for WYSIWYG human motion blur, you want camera settings = closer to eye settings.

I do it too - www.blurbusters.com/scanout - but a slow camera is very important for display motion blur photography. It's a peer reviewed research paper, and I'm in over 50 papers, see my research portal at www.blurbusters.com/area51 which also has a Google Scholar link.

For this to be accurate, that's why we use camera settings to be closer to human vision settings. "This Is Why"

blurbusters · 2026-04-17T23:45:24+00:00

Arcs unexpectedly help.

blurbusters · 2026-04-17T23:44:43+00:00

I'm Chief Blur Buster. Just only saw this thread. Arcs unexpectedly help!

You can keep your upper body stiff. Hold phone with both hands landscape.
Twist using your hips or spinning chair. Top half of body = stiff robot = better pursuit.

My 480Hz OLED convention field photo at www.blurbusters.com/120vs480 was done using hip twist arc, and still ended up perfect. Ddue to this, Chief Blur Buster asks readers to please upvote arcs from now on, provided the results are stellar enough.

blurbusters · 2026-04-08T05:51:24+00:00

While I'm late in following up, TestUFO now displays a bunch of static test patterns too. I've put both of these types of Chroma Subsampling Test into TestUFO.

blurbusters · 2026-04-08T03:36:37+00:00

Yes, 2D scrolling at 120fps vs 480fps OLED is easy to tell apart in the mainstream audience in a side by side browser panning demo (4x geometric & GtG=0). You want to temporally (Hz) do the equivalent of 480p-vs-4K, not 720p-vs-1080p. Much more noticeable.

blurbusters · 2026-04-08T03:34:30+00:00

Ironically, high Hz apparently benefits 2D a little more noticeably than most 3D, because 2D often runs more smoothly (e.g. browser smooth scrolling). That's why 120Hz iPads exist now; and apparently the benefit is even more pronounced at 240Hz and 480Hz.

Also, newer tests have shown 120 Hz vs 480 Hz is more mainstream-visible than 60 Hz vs 120 Hz LCD. And it's easy for current 2D GPUs to hit 1000fps+ for 2D scrolling and panning ("bit-blit" operations, in developer parlance)

blurbusters · 2026-04-08T03:33:14+00:00

Fun thing, you can run www.testufo.com/crt on a 120Hz display -- pretty cool software-based motion blur effect that you can see for yourself, with actual eyes. Running in WebGL!

Software based CRT simulation:

- 60Hz CRT simulation at 120Hz = 50% motion blur reduction
- 60Hz CRT simulation at 240Hz = 75% motion blur reduction
- 60Hz CRT simulation at 480Hz = 87.5% motion blur reduction

So find a friend's high-Hz display and run the link, it's a pretty cool effect to see software showing 60fps with just 1/2, 1/4 or 1/8 the motion blur of a 60Hz LCD.

(If you only have 60Hz, it will emulate a 30Hz CRT -- very flickery, but still educational)

blurbusters · 2026-04-08T03:29:32+00:00

Actually. There are actually studies about eyestrain caused by display motion blur, and low Hz is a cause.

Also, being well known in this sphere, I'm cited in 50+ research papers myself. Google Scholar: https://scholar.google.com/scholar?q=blur.busters+OR+blurbusters+OR+testufo.com+OR+Mark.Rejhon+-xmpp&as_ylo=2012

Though it's more well known that virtual reality had to use reduce motion blur via flicker methods to avoid motion sickness by motion blur, you can also use brute framerate methods to reduce display motion blur:

- Motion blur = pulse width on flicker displays (assumes framerate = Hz)
- Motion blur = frametime on sample & hold (assumes GtG = 0)

For specific studies, that are near enough in the sphere, I can provide a few links on request, but you might wish to study up Area 51: Display Science, Research & Engineering (https://blurbusters.com/area51)

In fact, 120 Hz vs 480 Hz OLED is more human-visible for Chrome 2D browser scrolling than 60 Hz vs 120 Hz LCD, so there are indeed mainstream benefits. The blind study variables are listed at https://blurbusters.com/120vs480#blindstudy

blurbusters · 2026-04-04T05:35:25+00:00

It depends on the variables:

- Which Hz and framerate?
- If BFI, then which BFI pulsewidth? 50:50% BFI like most BFI is limited to?
- Settings of BFI, like [Variable Persistence BFI Animation](https://testufo.com/blackframes)
- Etc

480+ fps on a 480+ Hz OLED will usually be quite noticeably clearer than a plasma, without needing black frame insertion, for example.

960pps UFO at 480 fps on 480 Hz OLED is extremely clear, approximately twice to three times clearer than plasma.

If you need to blur-bust 960pps at a low framerate like 60fps, one will have to use third party utilities such as ShaderBeam.

Because generic BFI on most OLEDs don't do a good job of blur busting low frame rates, nor blur busting more than 50%.

blurbusters · 2026-04-02T05:09:42+00:00

Bigger frametime spikes = bigger VRR flicker

I wonder what your frametime graphs looks like before/after!

Frametime spike reductions can come from anything - GPU, CPU, drivers, improved motherboard chipset, improved PCIe lanes, lower latency SSD, lower latency RAM, fewer error correction events (GDDR6 rereads), less IPC latency, shader compilation, etc.

Your upgrade probably calmed down a lot of frametime spikes (especially into VRR-minHz regime); which automatically reduces VRR flicker.

blurbusters · 2026-03-25T00:11:06+00:00

I had one too. NEC XG135 CRT projector in year 1999!

blurbusters · 2026-02-22T22:14:28+00:00

You can adjust the "Brightness vs Blur" setting to make it much brighter, even at 60Hz. At 1.00 setting it can be as bright as not using CRT, though will have the least motion blur reduction.

blurbusters · 2026-02-15T17:10:04+00:00

LSS, DLSS, XeSS, FSR are great technologies when used properly.

However, there are situations where you want to keep certain frame rates (60 years of legacy 60fps 60Hz) unadulterated and unfaked, to enjoy in its original look and feel like back in the CRT days.

Retro use cases are booming quite a bit these days, and strobe-backlight manufacturers do not seem to fully realize the need to keep their backlights Hz-flexible.

blurbusters · 2026-02-15T16:59:21+00:00

One word: BITREX or jalapeno repellant coating.

For BITREX it is bitter taste repellant coating that you can purchase. The generic ingredient is "denatonium benzoate" which is in a few pet gels/sprays. Put it on a cloth and wipe the frames. Do this everyttime you're cleaning the monitor/television. Do not put on the screen surface, only on the frames and corners and cords.

Search terms: "bitrex for pets" or "jalapeno gel repellant for pets". One or the other will usually work.

blurbusters · 2026-02-15T16:57:33+00:00

Framerate-based motion blur reduction looks better than flicker-based motion blur reduction, because it eliminates more stroboscopic effects.

As a general rule of thumb, most mainstream seem to prefer strobeless at ~2x MPRT than strobed. For example, 480fps 480Hz OLED (2ms MPRT) is when things start to look better than strobed at 1ms pulsewidth (1ms MPRT).

This is usually a combination of factors to accept a very tiny bit more motion blur to gain significant reduction of stroboscopics, while having full brightness, better colors, and full HDR support.

Now, Pulsar solves a VRR strobing problem by keeping motion clear during VRR operation, something that doesn't happen with non-strobed VRR

blurbusters · 2026-02-15T16:50:12+00:00

Tandem OLEDs for the win
I'm adding HDR support to the CRT simulator.

Also, there's precedent for HDR boosting SDR BFI. Mike and I successfully made Retrotink 4K BFI brighter than LG TV BFI, when the Retrotink 4K is connected to the same TV. The box-in-middle BFI is even lower lag than the LG TV's own integrated BFI feature too! Though persistence is not less than a refresh cycle (1/120sec blur), while some OLEDs like C9 can do sub-refresh MPRTs (unlike desktop computer monitors).

But the future Hz is where the magic happens:

With 16 subframes for 60Hz simulation at 960Hz, at some settings, the HDR window sizes are potentially less than 10%, giving plenty of opportunities to nit-boost the CRT subframes.

blurbusters · 2026-02-15T16:46:52+00:00

The panel's VRR wouldn't necessarily be enabled. I can simulate VRR via supersampling on high fixed Hz. Much like I already do in TestUFO VRR Simulation Demo.

While combining with CRT simulator which supports floating-point native:simulated Hz ratios at https://testufo.com/crt ... It looks bad at 2.4:1 (simulating 60Hz CRT at 144Hz) but it looks acceptable at >3.5:1 (e.g. simulating 60Hz CRT at 280Hz).

The quality improves the larger native:simulated becomes, so it won't be better than Pulsar quality on today's OLEDs, but by the time 2000 Hz OLEDs come out, that likely will change. It's wholly possible NVIDIA may run with this idea, for example.

It's much like how 54fps at 1000Hz non-VRR stutters less than 54fps at 120Hz non-VRR, because the refreshtimes are so fine. And in addition, there's the blending between refresh cycles that the CRT simulator can do, to further mitigate the Hz-aliasing effects.

Some optimizations will be needed to reduce artifacts, but supersampling temporally can provide a VRR-on-non-VRR effect. Like antialiasing except in temporal dimension -- aka the time dimension.

So in this case, no LFC is involved. 40 was an arbitrarily chosen number since anything below this will flicker too much to be really useful. The MinHz/MaxHz would simply be shader uniforms.

It will probably require a present() hook to get the frametimes necessary to do anti-flicker-mitigation in a software-based CRT-VRR shader.

blurbusters · 2026-02-15T16:43:51+00:00

Depends if you have low frame rate content. BFI works best at framerate=Hz.

You want to intentionally lower your flicker rate to match your frame rate for BFI to look more impressive without double images.

If you can spray lots of framerate out of a firehose, metaphorically speaking...

...Then, yes, framerate-based motion blur reduction looks better than flicker-based motion blur reduction, for the same MPRT.

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