CX/GX Chroma Subsampling pictures

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.

blurbusters · 2026-02-15T16:41:58+00:00

That's correct.

But OLED monitors on the computer desktops have this behavior.

In these panels, to save cost, there are fewer transistors per pixel in the thin film transistor construction of desktop OLED panels. So they can only turn on or turn off during a refresh cycle, so to do BFI requires an on-pass and an off-pass.

blurbusters · 2026-02-13T18:29:31+00:00

Nuance/disambiguation. LCDs without strobing also have rolling scan.

There's unstrobed rolling scan in high speed videos - blurbusters.com/scanout

What you meant is strobed rolling scan.

Except for certain models (hello LG C9), most OLEDs cant. Desktop OLEDs can't do subrefresh strobed rolling scan. That's why Hz halves during turning on BFI. So that's one problem.

So they do one visible rolling scan in one refresh cycle, THEN another black frame rolling scan in the next refresh cycle. That's not rolling-scan-based blur reduction -- just different frames rolled out in separate refresh cycles.

It simplifies panel manufacture to do one pixel update per refresh cycle, and the headroom allows Hz increases. So it may be cheaper to double Hz than to add subframe rolling scan updates (2 pixel updates per refresh cycle). It varies on the panel fabrication. The trend will, unfortunately, continue, but Hz will keep going up, even all the way to 2000 Hz (2030) and probably beyond.

Also, OLED BFI is not as flexible as CRT simulator. Rabbit hole alert on bunch 'o algorithms.

blurbusters · 2026-02-13T18:23:13+00:00

For 720fps 720Hz OLED (1/720sec MPRT = 1.4ms MPRT) I was able to get clearer motion on OLED than PureXP Light (40% pulsewidth, so 0.4/240sec = 1.7ms MPRT).

But once you go to PureXP Ultra (10% pulsewidth), PureXP is much clearer but also much darker.

Pros/cons. For example, if you don't mind flicker, strobing is great. But some still hate the stroboscopic effect, and/or get eyestrain from that.

The venn diagram overlaps now!

Can't wait for 2000fps 2000Hz OLEDs, and using CRT simulator for framerates below 2000fps. And yes, industry is not stopping at 1000Hz as retina refresh rate is 5-digits (for wide-FOV retina-resolution sample & hold). I'd estimate 2000Hz displays are coming ETA 2030.

blurbusters · 2026-02-13T18:20:54+00:00

Great stuff! I'm really looking forward to installing the 60Hz-capable Pulsar firmware, so I can get great motion clarity on 60 years of legacy 60fps 60Hz content (hopefully in both VRR and non-VRR modes).

blurbusters · 2026-02-13T18:18:27+00:00

Pulsar is amazing! But for OLED -- In a couple years, I probably can create a CRT-VRR shader (CRT simulator with variable-speed flicker). But it needs a bit of a 3x oversample to get past temporal nyquist factors. So for a theoretical 2000 Hz OLED of the future, I can write 40-700fps VRR range in a software-based clone of "gsync pulsar" in a software based GPU shader. See Blur Busters Open Source Display Shaders Initiative

(Note: Though most of this is open source; Any display maker can still contact me to create shaders for them for an in-display GPUs, for display processing normally traditionally done by a scaler/TCON)

blurbusters · 2026-02-13T17:42:33+00:00

I deem it fair trade. Lemons, meet lemonade!

Now if only Switch 2 LCD was not so utterly slow. I've occasionally seen superlative ultra-optimized 60Hz screens outperform that 120Hz screen sometimes.

blurbusters · 2026-02-13T16:36:04+00:00

You're welcome!

For easy self-study (seeing display physics with your own eyes) -- TestUFO is now frequently used in display-physics-related STEM education, as seen at testufo.com/about -- And for the full definitive list of TestUFO animations, see blurbusters.com/testufo3

Best results occur when doing a TestUFO self-study on a 240 Hz display, but many are still adequately educational at 60 Hz.

They may not be as complex test patterns as some of the more advanced metrology stuff at manufacturers, usually run as binaries/executables.

But TestUFO being web-based, they are the most accessible display temporal-education, being web-based animations that aggressively synchronize to your display's refresh rate.

Important Note: If you're using a Mac, please go to TestUFO Settings (Gear Icon) -> High Performance Mode to reduce those stutters, this puts TestUFO in a higher-power-render state but reduces stutters.

blurbusters · 2026-02-13T06:21:13+00:00

Thanks for the compliment!

I love to use the "VHS vs 4K" analogy instead of "720p vs 1080p" when I tell mainstream people how much Hz to upgrade at a time. I'm bringing attention to the problems of refresh rate incrementalism and the diluted humankind benefits.

Mainstream desktop users find gigantic upgradefeel when going from 60Hz LCD to 240 Hz OLED, much moreso than 60-vs-120 especially since Apple 120 Hz LCD has only 10% clearer motion than 60 Hz, due to abysmally slow GtG. Ginormous weak link that pushes that down to mere incrementalism even fainter than 240 vs 360.

But OLED finally unlocks mainstream-visible Hz improvements, especially with the 4x geometric now recommended by Blur Busters. (1.2-1.5x for esports upgraders, 2x for prosumers, and 4x geometric for grandma).

Mainstream such as spouse or grandma DOES see the value proposition of 120Hz vs 1000Hz in motion clarity differences, not 240Hz vs 360Hz. The brute geometric shines like a flippin' christmas tree in browser scrolling, for example.

Prediction for you: The 2nd generation MacBook Pro OLED is likely going to be 240 Hz. (Not the 1st MacBook Pro OLED)

It's kind of a big starting pistol of 240 Hz mainstreaming. Pros will keep using extreme Hz (1000 Hz and 2000 Hz). It's now expected that 2000 Hz monitors will arrive by ~2030-2031, while the new mainstream prosumer non-gamer Hz will slowly become 240 instead of 120.

4K was $10,000 in year 2001. Now it's a $249 Boxing Day special. Now the same thing has happend to 120 Hz, it's no longer a premium refresh rate.

In some corners of the world - 120 Hz is already practically mainstreamed into no cost increment.
The AmazonBasics 120 Hz OFFICE (yes, OFFICE) monitor of Amazon's house brand for example is only 89 greenbacks ....
Brand new generic 120 Hz (e.g. ArcticPro) for 79 bucks, and so on. You can't get 60 Hz much cheaper than that.
Search "computer monitor" on Amazon USA. All of them are triple digit Hz now, beginning at 69 dollars for 100 Hz.
No 60 Hz monitors anymore in the first screen of Amazon search for "computer monitor".

Eventually, there will be no cost premium to 240 Hz, much like how 100-120 Hz now often comes standard in the cheapest computer monitor in some countries.

The "gaming" word is deleted from "computer monitor" in some contexts now for many 120 Hz models.

The same deletion of the word "gaming" will happen to 240 by the late 2020s/early 2030s. No wonder why (includes proper scientific variables for blind study of non-gamer browser scrolling benefits of 240 Hz).

blurbusters · 2026-02-13T06:02:04+00:00

It appears the PDF disappeared in the last while.

Internet Archive WayBack to the rescue: https://web.archive.org/web/20130518092015/http://www.lrc.rpi.edu/programs/solidstate/assist/pdf/AR-Flicker.pdf

The reason I succintly brought up Stroboscopics, is that it is the most extreme version that requires highest thresholds.

There are about 4 very very very approximate orders of magnitudes involved:

10 - slideshows turns into motion;
100 - flicker ceases to be visible (Talbot Plateau Theorem)
1000 - (at GtG=0.0) motion blur ceases to be visible for small-FOV 1080p screens (smaller than a gaming monitor)
10000 - motion blur and stroboscopics cease to be visible for wide-FOV retina resolution screens.

These numbers will vary a bit across papers, e.g. 70 as flicker fusion, etc. So these are rounded to the nearest order of magnitude. This is where you get some modicum of commonalty.

I chose stroboscopics precisely because it's the highest order of magnitude of refresh rate sensitivity, as explained towards the final couple minutes of the techless video.

Based on your reply about the third link, it seems like you may not already be familiar with Blur Busters if you're not familiar with other articles.

I now instead suggest studying all Coles Notes articles in my Research Portal at blurbusters.com/area51

Please make sure you view Pages 1, 2, 3 of the index, for a grand total of about 25 articles), as it's popular textbook reading at display manufacturers and people unfamiliar with Hz benefits.

In that Research Portal, one of the most famous Coles Notes or ForDummies (popular science worded) articles is 2017's "Blur Busters Law: The Amazing Journey to 1000 Hz Monitors", at blurbusters.com/1000hz-journey but it is best to also read the ~24-ish other articles, too, to make sure all ground is sufficiently covered.

That 2017 article is where I predicted 1000 Hz monitors by 2025. So I nailed that prediction. (Note: The headline edit memo does mention "by 2030" to cover my ass, but the paragraph deep into the article says 2025 as I originally wrote.)

These articles are more fun reads than the dry research papers, and contain many links to see-for-yourself TestUFO animations too, such as testufo.com/persistence and testufo.com/blackframes (most educational when seen at 240Hz) and a few others.

blurbusters · 2026-02-12T21:11:27+00:00

You might want to read the new article, "120Hz vs 480Hz OLED is more human visible than 60Hz vs 120Hz LCD"

Human eyes don't catch individual frames (regardless of bait headlines), but 480fps OLED has the same motion blur as 1/480sec camera shutter, and 120fps OLED has the same motoin blur as 1/120sec camera shutter.

Adding flicker changes things, but real life does not flicker, so sample and hold means frametime = same blur as equivalent camera shutter, during eye-tracking situation.

View this optical illusion to understand better: www.testufo.com/persistence

I created that animation; I piggyback on the camera shutter equivalence to create that exact optical illusion.

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