Good News Everyone: 60Hz Single Strobe Options

Ask about motion blur reduction in gaming monitors. Includes ULMB (Ultra Low Motion Blur), NVIDIA LightBoost, ASUS ELMB, BenQ/Zowie DyAc, Turbo240, ToastyX Strobelight, etc.
JDnoob
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by JDnoob » 27 Jan 2021, 23:36

Yes! The level of engineering effort put into the strobing on this Vizio is truly amazing. It's so sad to see that backlight strobing is an afterthought on so many gaming monitors. There are standouts like the XG270, but they almost always have limitations like the lack of 60hz-single-strobing. MPRT on these monitors is also rarely as good as the aforementioned Vizio.

There is good reason why I currently use the 65" Vizio as my primary display. I have spent a quite substantial amount of effort looking for monitors to beat the Vizio in terms of the overall gaming experience with great backlight strobing and picture quality. I have found that unless you are a Esports gamer (in which case you'll want a 240hz+ monitor, obviously), the Vizio is unfortunately very difficult to beat with a monitor, all things considered. Giving up the 4k resolution and 5000:1 contrast ratio for a 1080p display that at best has similar strobe quality and lacks 60hz-single-strobing doesn't make much sense.

The Oculus Quest 2 as mentioned by the Chief Blur Buster looks amazing with 0.3 MPRT! But VR isn't particularly convenient for most use cases. I still believe the P-Quantum X is probably the best non-VR display around for backlight strobing, especially with its massive contrast ratio and 4k resolution. It's large form factor and only decent viewing angles are an understandable turnoff for many though. I'm very excited to see a push for more monitors with 60hz-single-strobing!

Lucario
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by Lucario » 01 Feb 2021, 15:14

Bravia A8H also does it, but best I've seen is Motionflow (Sony's motion interpolation tech) + BFI for 24-60 fps locked video/games, it beats 120 source + BFI. Looks like it might be 240 BFI. Of course the input lag will be big there, actually not too bad for peaceful games.

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AddictFPS
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by AddictFPS » 02 Feb 2021, 07:30

Lucario wrote:
01 Feb 2021, 15:14
Bravia A8H also does it, but best I've seen is Motionflow (Sony's motion interpolation tech) + BFI for 24-60 fps locked video/games, it beats 120 source + BFI. Looks like it might be 240 BFI. Of course the input lag will be big there, actually not too bad for peaceful games.
Sony A8H is very different, is OLED without backlight like LG CX, both have a limit of 4.16ms MPRT. Rtings review show the max BFI frecuency for A8H is like LG, 120 black frames/s, i not find any reference to A8H reaching 240 BFI (2.08 MPRT).

https://www.rtings.com/tv/reviews/sony/a8h-oled
https://www.rtings.com/tv/reviews/sony/a8h/settings

60Hz with 4.16ms MPRT in current OLED max. brightness, result in only 60nits. Vizio can do 60Hz with lower MPRT and 100nits.

The fact of be able in A8H to mix custom levels of interpolation and BFI is interesting for 60p video :) if interpolation random artifacts not ruin the result. Not know if LG CX has this feature. But both TV need be outside GameMode for use interpolation. Vizio with BFI inside GameMode, result in 6x less input lag than A8H Interpolation+BFI. For 60p games A8H with this config is extremely slow.

Rtings A8H:

4k 60 Hz (GameMode) 18.5 ms
4k 60 Hz (Outside Game Mode) 93.5 ms / 16.6 = 5.63 frames !

Rtings P65-F1:

4k 60 Hz (GameMode) 15.3 ms

Move mouse, click button, prees key, move driving wheel, and 0.1 seconds later finaly screen show the event. Even simple desktop tasks like move pointer sucks, imagine gaming. I hate this super laggy input feel, unvearable.

Lucario
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by Lucario » 04 Feb 2021, 20:20

Sorry, that "240 BFI" is just a hazard guess from what I saw improvement from 120 BFI to interpolation + BFI. I could do video if you're interested.

JDnoob
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by JDnoob » 05 Feb 2021, 03:11

I 2nd pretty much everything AddictFPS said.

The biggest issue with the LG OLEDs and other OLED TV's that use the LG panel seems to be the 4ms MPRT at 60nits limit. I dare say 60hz-single-strobbing on the LG OLED's is simply too dim for most. And strobe-width isn't fully adjustable with brightness like it is on the Vizio.

Below seem to be the three most interesting TV's when considering backlight strobing. Flagships of LG, Samsung, and Vizio respectively. TCL and Sony seem to underperform so I've omitted them. Bare in mind RTINGS BFI testing is extremely limited and they only specify that these pursuits were taken at backlight 100%.

LG CX
cx-bfi-large.jpg
cx-bfi-large.jpg (43.01 KiB) Viewed 16718 times
https://www.rtings.com/tv/reviews/lg/cx-oled

Samsung Q90T
q90t-bfi-large.jpg
q90t-bfi-large.jpg (38.09 KiB) Viewed 16718 times
https://www.rtings.com/tv/reviews/samsung/q90-q90t-qled

Vizio P-Quantum X 2019
p-series-quantum-x-2019-bfi-large.jpg
p-series-quantum-x-2019-bfi-large.jpg (26.84 KiB) Viewed 16718 times
https://www.rtings.com/tv/reviews/vizio ... tum-x-2019

It would seem that Vizio > Samsung > LG > Other

Its difficult to see the difference in brightness over photos, but its clear the Vizio has tons of headroom for lower MPRT. I think the fundamental problem with OLED is simply brightness. Very low CRT-like MPRT at good brightness can only be achieved by a massively bright strobe. LCD backlights are still 3x brighter than OLED at the high-end (3000 nits vs 1000 nits).

That being said, the LG should probably do much better mathematically speaking with 1000 nits. The strobe on the LG is likely nowhere near 1000 nits for MPRT and brightness this bad. I'm not sure if LG is already doing a rolling-scan strobe to combat fullscreen-brightness-limitation on OLED. If they are not, that might be an area of further improvement.

A perfectly implemented 1000 nit strobe at 60hz should produce 1.7ms MPRT 100nits.

The 1000 nit Vizio P65-F1 is within the margin-of-error of this target. LG CX is nowhere close, despite being capable of 1000 nit highlights in HDR.
Last edited by JDnoob on 05 Feb 2021, 16:15, edited 1 time in total.

thatoneguy
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by thatoneguy » 05 Feb 2021, 04:36

LG CX does 799 nits on a 2% window only on HDR. You need to force HDR to make the strobe even useful.
You need 1000 nits on a 100% window for 1.7 MPRT.
In reality neither of these models reach that brightness.

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AddictFPS
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by AddictFPS » 05 Feb 2021, 14:41

Vizio link is 2020, 2019 here https://www.rtings.com/tv/reviews/vizio ... tum-x-2019

To take into account in these two Vizio TV and the 2018 P65-F1 also, brightness under 100% with strobe mode Off result in 120Hz backlight flicker, this is a step back. Flicker should only occur when strobe is On
Unfortunately, this TV uses PWM to dim the backlight, and there is a 120Hz flicker at all backlight levels other than max. This results in duplications in motion, which might be noticeable in certain content.
If with 24p film, intead use 24Hz sample-and-hold, there are 120Hz refresh + 120Hz PWM, 4 replies of the frame ? not sound fun. Strobing only has motion quality if is single strobe. JDnoob, your P65-F1 has 24Hz sample-and-hold mode ?

Also typical pixel array for monitor is RGB, for the standard clear type fonts. But Vizio use RBG, need custom clear type config. LG use RGBW, so sure also need custom SO text tweak. Clear type is subpixel process for smoothing. I wonder if games subpixel processes like pixel shaders or AA also are designed for default RGB. If yes, seems than any screen out of RGB is a small loss of sharpness for any subpixel optimization than do not take into account the current pixel array.

Rtings has reviewed LG CX two times, one like TV, and another like monitor with GameMode On. The BFI capture of the monitor review, with CX 48", is more clear than from TV review, maybe also use a newer firmware.

https://www.rtings.com/monitor/reviews/lg/48-cx-oled
https://i.rtings.com/images/reviews/mon ... -large.jpg

LG CX 48 120Hz BFI High 4.16ms MPRT 120 nits
Image

Excellent performance, LG CX is not the king in MPRT, but 100Hz and 120Hz all screen with this motion quality 100% crosstalk free, with the native constrast of OLED (FALD at subpixel level) is amazing ;)

With 60Hz is the same motion blur, but only 60nits, is realy very dimm. LG need improve brightness to much, is far away of reach the dream of BFI + HDR. But in OLED, more brightness = more risk of permanent burn-in. Even the 120nits at 120Hz are not constant, if one static image is show, ABL reduce brithness randomly, this is a bit annoying for some people.

Here is where this Vizio VA LCD result interesting, cost less, remove the burn-in risk, maintain brightness sustained with strobing, can reach more brightness, FALD improve contrast, each year P series increase FALD zones and peak brightness :) With 60Hz almost crosstalk free with 2018 100 FALD zones and rolling scan, nice work.

Expensive gaming monitors should have at least this Vizio 2018 performance for 60p locked games, 65" for desktop is crazy :) and the good gaming monitors have much less 60Hz input lag than TV in gamemode, mainly due to take advantage of 240+ Hz scanout.

TV are mainly optimized for video, and more than 120Hz is very unlikely, only in long term if consoles continues the Hz race, or HFR video fashion begin. But monitors are currently FHD 360Hz UHD 160Hz, in a unstopable race :) with RGB pixels.

JDnoob
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by JDnoob » 05 Feb 2021, 18:14

You don't need 1000 nits on the 100% window for a 1000 nit strobe. Strobing does not have to be global but can instead be scanned down the screen using a much higher small-window-brightness. Many displays can also hit higher brightness for short strobes then they can in normal use. LG may already be using a rolling-scan but they are clearly not pushing the OLED very hard for better MPRT. It's possible that LG won't push it further simply because driving OLED pixels that hard, even for extremely brief periods, could accelerate burn-in significantly.

I fixed the link.

Unfortunately, the only way to remove the 120hz PWM is to set the backlight to maximum. Otherwise you have a 5x image effect for 24fps content. Not ideal but also probably not very noticeable with all the blur in movies. I actually prefer PWM in most games over sample-and-hold. Looks weird, but easier to make out fast moving objects, albeit nowhere near as good as single-strobing.

I wouldn't read too much into the different subpixel layout. Even without ClearType, its only really an issue at 100% scaling, which few people use at 4k anyway. I highly doubt any games will be effected at all. Use BGR ClearType or 125%+ scaling if it bothers you.

Much bigger problem with the Vizio is that you need to use chroma subsampling for low input lag at 4k. With 4k full-RGB, you have 25ms of input lag instead of 15ms. You really need 150%+ (1440p scaling) for chroma subsampling to not effect colored text significantly. Note this problem is fixed by HDMI 2.1. Chroma subsampling doesn't effect games but is important for desktop use. This could actually be a deal-breaker if you want to use the Vizio very close with 100% scaling. Need 150%+ scaling to solve this.

Big advantage of LG CX is crosstalk-free 120hz, but 4x MPRT as Vizio P65-f1. 100hz on Vizio is best for 1ms MPRT with little crosstalk.

If using strobing 100% of the time, I'm not sure the Vizio has any more input lag than a good gaming monitor. Monitors clearly have less input lag with sample-and-hold, but strobing generally adds half a frame of input lag. I need better equipment to measure Vizio exactly, but I think BFI adds little input lag. Combining the Vizio with a 240+hz gaming monitor could be one way to give you the best of both worlds, whether you want strobing for scenic games or high-hz-sample-and-hold for competitive games.

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Re: Good News Everyone: 60Hz Single Strobe Options

Post by Chief Blur Buster » 06 Feb 2021, 01:01

JDnoob wrote:
05 Feb 2021, 18:14
Strobing does not have to be global but can instead be scanned down the screen using a much higher small-window-brightness.
Yes, this is ideal if it's done well.

The problem is that it's hard to do it well -- and cheaply. Light leaks from the "ON" section to the "OFF" section, creating more strobe crosstalk in scanning backlight operation, unless a lot of engineering money is spent on the scanning backlight to reduce backlight leakage. Now, today, cheaper MiniLED backlights, that can be put flush to the back of the panel, has helped quite a bit -- and scanning backlights should be attempted again.

Currently, global-flash strobe backlights is the only way to go almost 100% crosstalk free. Some LCDs manage to do this, like the Quest 2 virtual reality LCD which has a supreme GtG heatmap par excellence -- zero strobe crosstalk for top/center/bottom.

However, FALD scanning backlights have the ability to do vastly superior contrast, and possibly also simultaneous strobing+HDR if there is sufficient nit headroom. (e.g. multi-thousand nits for example)

Blur Busters originally launched as www.scanningbacklight.com in year 2012, in creating an Arduino Scanning Backlight experiment before LightBoost was discovered as a simpler/superior alternative. I still have a nearly-decade-old Scanning Backlight FAQ and I wrote Electronics Hacking: Creating a Strobe Backlight in year 2013.
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JDnoob
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Re: Good News Everyone: 60Hz Single Strobe Options

Post by JDnoob » 06 Feb 2021, 17:53

I understand backlight leakage can present some issues on LCD but a rolling-scan should be more or less simple to implement on OLED?

Any knowledge on if LG OLEDs are already doing this?
Screenshot 2021-02-06 145721.jpg
Screenshot 2021-02-06 145721.jpg (237.08 KiB) Viewed 16537 times
Source: https://blurbusters.com/faq/oled-motion-blur

I assume a global strobe on OLED would be highly inefficient.

Referring to 60hz strobing on the LG CX:

One would think LG could get better than 60nits for 4ms MPRT if they were using a rolling-scan.

The LG CX measures 460 nits on the 25% window (4ms rolling-scan). This should produce 115 nits for 4ms MPRT, not 60 nits.

Maybe they are not driving the pixels as hard during strobing as they do in HDR to prevent burn-in.

Can we expect more from OLED BFI or is LG already doing everything they can? With these numbers, I'm most interested in LCD's for strobing until MicroLED.

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