LG OLED CX 120Hz BFI

High Hz on OLED produce excellent strobeless motion blur reduction with fast GtG pixel response. It is easier to tell apart 60Hz vs 120Hz vs 240Hz on OLED than LCD, and more visible to mainstream. Includes WOLED and QD-OLED displays.
flaviowolff
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Re: LG OLED CX 120Hz BFI

Post by flaviowolff » 15 Sep 2021, 06:19

Hello, I have a quick question.
If I want to use OLED Motion Pro on High for 120hz gaming, I understand that I should keep my framerates on 120fps. But, as I also use gsync, I tend to cap it at 117fps. Would it make much of a theoretical difference?
I will test it later, but it's always good to hear your opinions.
Ty!

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Re: LG OLED CX 120Hz BFI

Post by RonsonPL » 15 Sep 2021, 17:40

I might be wrong, but I think OLED TVs don't support low persistence modes when Variable refresh rate feature is enabled.

If I'm right, you'll need exactly 120fps for the motion clarity to be good.
I don't know much about TVs, but hopefully you can make it work at 100Hz too, and this would surely help with games which won't hold 120fps unless you use a liquid nitrogen cooling and spend months on finding the best CPU and RAM in the world (and hire PROs to set it up for you so you can play for 2 minutes ;) )

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Re: LG OLED CX 120Hz BFI

Post by flaviowolff » 16 Sep 2021, 06:17

RonsonPL wrote:
15 Sep 2021, 17:40
I might be wrong, but I think OLED TVs don't support low persistence modes when Variable refresh rate feature is enabled.

If I'm right, you'll need exactly 120fps for the motion clarity to be good.
I don't know much about TVs, but hopefully you can make it work at 100Hz too, and this would surely help with games which won't hold 120fps unless you use a liquid nitrogen cooling and spend months on finding the best CPU and RAM in the world (and hire PROs to set it up for you so you can play for 2 minutes ;) )
:D

Good point. VRR should be disabled, thus I don't need the -3fps cap, maybe only the -0.007fps cap for low lag vsync, which wouldn't ruin the low persistance mode, right?
As for the games, I'm talking about old games, for sure, which can hold steady 120 100% of the time.
Thanks

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Re: LG OLED CX 120Hz BFI

Post by Chief Blur Buster » 17 Sep 2021, 12:05

flaviowolff wrote:
16 Sep 2021, 06:17
Good point. VRR should be disabled, thus I don't need the -3fps cap, maybe only the -0.007fps cap for low lag vsync, which wouldn't ruin the low persistance mode, right?
It would actually benefit the low persistence mode.

But you may want to try something superior (albiet slightly harder to adjust), RTSS Scanline Sync or the new Special K clone of it, which can achieve perfect framerate=Hz at low latencies without tearing and stutter.
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Re: LG OLED CX 120Hz BFI

Post by NeonPizza » 20 Oct 2021, 03:25

I'm extremely disappointed by my 65" C1's motion response time. It's like a horrible smearing hurricane of motion blur slathered on top of a measly 300p lines of motion resolution the moment the in-game camera starts moving beyond a snails pace. It's like being drunk off 20 beers with vasalein smeared all over your eyes. How is THIS enjoyable!? CRT's perfected blur-free motion since the 80's, 90's up until their demise in the mid 2000's....Here we are in 2021, and these overly expensive TV's can't even do that right, and it's hands down imo the most crucial and important aspect of a TV. sure everything is important. but what good are true blacks if the screen, your character etc are constantly being smacked by blur and only 300p motion which is a far cry from 1080p even....and these TV's are native 4K. pathetic.

Bioshock Infinite & Doom Eternal on my PS4 Pro for example, running in 60fps of course were an absolute nightmare to play on the C1(Even worse on the C9...that one actually a bit more blur) because of it. The motion blur gives me eye strain, fatigue and almost makes me feel sick. It makes these games look ugly, it takes me out of the experiences, breaks immersion and always has me dropping out. i just can't do it.

I'm a huge fan of CRT motion(Zero Blur. ding ding!) and it makes a WORLD of a difference. Motion Blur and low motion resolution completely sour and botch the experience for me. I can't stand gaming on my C1 because of it. i dont game at 30fps anymore, only 60fps and hopefully 120fps when it's not so scarce. But i dont know, once again i've hit a fork in the road and i cant find the right TV that suits me needs.

I also have a Panasonic S60 plasma, which has MUCH better motion. 700 lines of motion res' with minimal Blur. it's still no CRT, but it completely spanks the C1 in this area. BUT, it has 34ms of lag, it's dim, grey-whites, blacks aren't as deep as OLED etc. I mean, the C1's motion is only worth a damn when you turn on MotionPro BFI 'HIGH'...It actually gets close to the S60's motion at this point, but as expected brightness plummets and you're left with a dreary dim lifeless picture, with more shadow detail crushing, double the input lag and that dreaded irritating eye melting FLICKER. lol

ugh. Look, i love nearly everything else about the C1 with the exception of game mode's picture which btw looks dimmer, less punchier, noticeably softer and less refined than the other modes like ISF Bright/Dark Room, to the point where i don't even want to go back to Game Mode. :P Ultimately the motion breaks this TV and i regret forking over $3400 to get it when i can't even stomach looking at the thing the moment things start moving.

seriously, what's it going to take to get Blur free or nearly blur free motion with about 1080 lines of motion resolution on a 65-75" HDTV?
There were a few plasmas capable of 1080p motion, but the majority had high latency.

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Re: LG OLED CX 120Hz BFI

Post by jorimt » 20 Oct 2021, 09:29

NeonPizza wrote:
20 Oct 2021, 03:25
I'm extremely disappointed by my 65" C1's motion response time. It's like a horrible smearing hurricane of motion blur slathered on top of a measly 300p lines of motion resolution the moment the in-game camera starts moving beyond a snails pace.
The C1's pixel transition time (sometimes known as GtG) is actually virtually near zero, unlike LCDs, but like LCDs, what you're instead experiencing is the sample-and-hold nature of an OLED display. It's the MPRT (motion picture response time), which is limited directly by the frame/refresh rate interacting with the sample-and-hold nature of the display, causing image persistence in this case.

The only thing that will reduce image persistence on a sample-and-hold display is BFI, which the C1 does feature, but it will impact input lag to an extent (not sure by how much on the C1 in particular).
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Re: LG OLED CX 120Hz BFI

Post by NeonPizza » 20 Oct 2021, 13:03

jorimt wrote:
20 Oct 2021, 09:29
NeonPizza wrote:
20 Oct 2021, 03:25
I'm extremely disappointed by my 65" C1's motion response time. It's like a horrible smearing hurricane of motion blur slathered on top of a measly 300p lines of motion resolution the moment the in-game camera starts moving beyond a snails pace.
The C1's pixel transition time (sometimes known as GtG) is actually virtually near zero, unlike LCDs, but like LCDs, what you're instead experiencing is the sample-and-hold nature of an OLED display. It's the MPRT (motion picture response time), which is limited directly by the frame/refresh rate interacting with the sample-and-hold nature of the display, causing image persistence in this case.

The only thing that will reduce image persistence on a sample-and-hold display is BFI, which the C1 does feature, but it will impact input lag to an extent (not sure by how much on the C1 in particular).
Ahhh, i see. I wish Sample and Hold would just die off already, but it looks like 'Micro' LED will have the same issue.
I can't stomach using BFI in Game Mode solely because of how much brightness you lose. The picture ends up looking super dim and lifeless. And the flicker is VERY distracting and kills my eyes when watching movies especially. I'm not too bothered by the double amount of latency though. The extra shadow detail crushing might be able to be corrected ala' calibration, but it doesn't matter when you factor in the brightness loss which ruins it all for me.

I'm either going to go back to my 60" Panasonic S60(Or hopefully find a 65" version in the Wild) a Sell my LG C1 and go for the Sony A80J OLED....I know the Sony's motion will be equally as bad as the LG, but at least it's Game mode will a lot better than the crap LG is whipping out. There's nothing else on the Market that will be able to top it, so.

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Re: LG OLED CX 120Hz BFI

Post by NeonPizza » 20 Oct 2021, 13:09

jorimt wrote:
20 Oct 2021, 09:29
NeonPizza wrote:
20 Oct 2021, 03:25
I'm extremely disappointed by my 65" C1's motion response time. It's like a horrible smearing hurricane of motion blur slathered on top of a measly 300p lines of motion resolution the moment the in-game camera starts moving beyond a snails pace.
The C1's pixel transition time (sometimes known as GtG) is actually virtually near zero, unlike LCDs, but like LCDs, what you're instead experiencing is the sample-and-hold nature of an OLED display. It's the MPRT (motion picture response time), which is limited directly by the frame/refresh rate interacting with the sample-and-hold nature of the display, causing image persistence in this case.

The only thing that will reduce image persistence on a sample-and-hold display is BFI, which the C1 does feature, but it will impact input lag to an extent (not sure by how much on the C1 in particular).
Also, regardless of the Q90A QLED being sample & Hold like the LG C1 OLED, due to the Q90A's slower motion response time, wouldn't there still be more motion blur/smearing?

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Re: LG OLED CX 120Hz BFI

Post by Chief Blur Buster » 20 Oct 2021, 13:33

NeonPizza wrote:
20 Oct 2021, 03:25
seriously, what's it going to take to get Blur free or nearly blur free motion with about 1080 lines of motion resolution on a 65-75" HDTV? There were a few plasmas capable of 1080p motion, but the majority had high latency.
We're already there with Blur Busters Approved LCDs.

There are certain LCD HDTVs with excellent strobe backlights now (check the best BFI images on RTINGS) that can beat plasma, but has a faint afterimage.

Very few LCDs get better than CRT, but a few do nowadays -- especially VR LCDs like Valve Index and Quest 2 which can do 0.3ms MPRT with zero contouring, zero noise, zero ghosting, and zero double-images, with less motion blur than a Sony FW900 CRT tube. VR LCDs are jawdropping.

Also, if you want CRT clarity, check CRT Nirvana Guide For Disappointed CRT-to-LCD/OLED Upgraders.
______

Also, you might want to know that "Lines of Motion Resolution" is an obsolete analog benchmark. Saying "motion resolution" is fine, but stay away from the "lines of..."

That discontinued "lines of..." non-resolution-independent motion-resolution benchmark is not applicable for today's era. So, please skip ever mentioning "Lines of Motion Resolution" anywhere on the Internet, here or otherwise. The garbage benchmark, please see Making Of: Why Are TestUFO Display Motion Tests 960 Pixels Per Second?. This will help you understand my giant disdain of yesteryear analog-era benchmarks being used in this digital era.

Even Samsung researchers agrees with me that "lines of motion resolution" is now an outdated benchmark, this Blur Busters motion resolution article is cited in this Samsung paper, 57‐2: A New Approach to Motion Frequency Metrics Quantifies Motion‐induced Blur (paywalled, alas -- ugh). And, in addition, Blur Busters / TestUFO is cited in more than 20 peer reviewed research papers (it shows the free excerpt that shows my name or my business that I founded).

I beg, I plead, do not use "Lines of Motion Resolution" anywhere on the Internet ever again. That outdated analog era benchmark needs to die except when discussed in legacy contexts (e.g. analog media and early digital media played on analog displays, including analog HDTVs).

The correct roughly-equivalent demand you need to make for 1080 lines of motion resolution today, is
"When Can I have a TV Capable of True Real-World 0.5ms or 1ms MPRT without artifacts?"
*artifacts can include contouring, double images, temporal dither noise, rainbow artifacts, ghosting, smearing, etc.

This is because of the Vicious Cycle Effect, where higher resolutions amplify motion resolution limitations. The analog benchmark starts to distort itself when trying to describe resolution independent situations. The motion blur of 1ms MPRT is identical at 1080p and 4K, but at 4K, pixels are smaller, so you see a delta again between stationary images and moving images.

For big screens getting close to CRT clarity, it's tough. Your options are:
- LG C9 or CX OLED HDTVs configured max BFI with 4ms MPRT (1/4th the blur of 60Hz); and
- Desktop Gaming Monitors that are Blur Busters Approved (with refresh rate headroom trick).
- Select LCD HDTVs with well-tuned strobe backlights (very rare).
- Virtual reality LCDs are the most superlative in exceeding CRT motion clarity today. They have 6x less blur than VR OLEDs. Virtual reality LCDs are exactly as sharp in fast motion as stationary, with 100% perfection, no artifacts, no double images, no ghosts, not even a phosphor ghosts which makes virtual reality LCDs better than CRTs. The only drawback is LCD greys, and lower contrast ratio, but they blew past CRTs in all other categories already.

To get CRT clarity today, you need to do the "1% cherrypicked LCD" technique followed by the refresh rate headroom trick (more time to hide LCD GtG completely in total darkness between refresh cycles), i.g. 240Hz LCD strobed at 120fps 120Hz, for zero-crosstalk operations.
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Re: LG OLED CX 120Hz BFI

Post by Chief Blur Buster » 20 Oct 2021, 13:35

Oh, I teach master classes at display manuacturers now.

Image

For some of the textbook education simplified to an easy "Popular Science" or "Coles Notes" format, see:

Blur Busters Area 51: Textbook Reading on Blur Busters Website

This is educational to CRT-era people only discovering that 1% of the best LCDs can now beat CRTs in motion resolution.
("Motion resolution" is fine. Just use "MPRT" or more modern benchmarks, not "lines of")

(Alas, large LCDs don't yet strobe crosstalklessly at large sizes yet, unless you're doing the 120Hz->60Hz QFT trick to refresh-headroomize it and get low-crosstalk 60Hz on a 120Hz LCD scanning out 60Hz refresh cycles in 1/120sec to create 8ms of VBI total darkness to hide pokey slow LCD GtG from human eyes -- good strobing headroom requires complete GtG100% hide)

We are Blur Busters. This is our specialty. To put it succinctly, we know this shit. :D
NeonPizza wrote:
20 Oct 2021, 13:09
Also, regardless of the Q90A QLED being sample & Hold like the LG C1 OLED, due to the Q90A's slower motion response time, wouldn't there still be more motion blur/smearing?
Measuring pixel response during strobing is different.

The game of LCD strobing is to try to hide LCD GtG in the blanking interval, to hide slow pixel response from human eyes.

Even an 8ms LCD can strobe better than a CRT, if it's 8ms GtG 100%, and the 8ms is occuring while the backlight is turned off.

Benchmarks on LCDs need to be done separately in non-strobed operation (fully visible pixel response) and strobed operation (partially visible or invisible pixel response).

See high speed video of LightBoost how strobing can sometimes hide LCD GtG:

phpBB [video]


Notice how most of the LCD pixel response is hidden from human eyes?

The problem is strobing is sometimes done very badly, some of the explanations is explained at Electronics Hacking: Creating a Strobe Backlight, a FAQ I wrote in year 2013 in the early days of Blur Busters.

Now, crosstalk of strobing is simply a function of how much LCD GtG is hidden in total darkness between refresh cycles. Here's example artifacts from percentages of incompletely hidden GtG:

Image

Most terrible strobe backlights only hide 75% of GtG, leaving 25% to be human visible.

But the best strobe backlights can hide GtG 99% or 99.5% or 99.9%, especially when combined with the refresh rate headroom trick to create giant VBI's that you can drive truck through, to hide LCD GtG better between refresh cycles. A 60Hz refresh cycle scanning-out in 1/240sec (4ms) allows up to about 12-13ms of dark time between strobe flashes, more time to hide LCD GtG between refresh cycles.

So even if LCD is 8ms GtG, your eyes only sees 0.5ms MPRT.

Remember GtG and MPRT are different.
GtG = time that a pixel takes to change color (pixel fading from one color to the next)
MPRT = time that a pixel is visible for (visible to eyes).


See Pixel Response FAQ: Two Pixel Response Benchmarks: GtG versus MPRT

The bonus is GtG can be made invisible to eyes if all of LCD GtG is 100% occuring while the backlight is turned off. Only a few LCDs manage to do this perfectly.

MPRT is what you should be worried about, GtG can be hidden by a good strobe backlight sometimes, the problem is not all strobe backlights are good, and GtG just needs to be improved to be fast enough to finish in the VBI (blanking interval between refresh cycles).

Also, there is a law of physics issue called Talbot-Plateau Law that favours LCD. You need to strobe brighter to strobe briefer. That makes it easier to keep image bright at low MPRTs. OLEDs currently have a hard time doing this. Some LCDs such as XL2546 strobe at 1000-2000 nits to allow it to average ~350 nits. OLEDs have a hard time doing BFI strobe brighter to allow reductions of motion blur.

I love OLEDs but I am cognizant of some of the realities and practicalities that caused the best cherrypicked 1% LCDs to have less motion blur than CRTs (such as the superlative VR LCDs released by Valve and Oculus).

Randomly buying an LCD is always going to be crappy, so one has to carefully shop for the best LCD strobing *and* then do a few additional tricks to reduce strobe crosstalk (e.g. refresh rate headroom).

Tomorrow, the ultimate ergonomic comfort later this century is blurless sample-and-hold, because MPRT(100%) can never be less than one refresh cycle on a sample and hold display. But at 1000fps 1000Hz, the MPRT becomes 1ms. So you have flicker-free CRT motion clarity sample and hold! So that's why we're huge fans of blurless sample-and-hold.

Image

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Sadly, you cannot get better than 4ms MPRT with the best LG OLEDs configured with BFI enabled.

Note: refresh rate headroom trick isn't necessary for OLEDs, like it is for LCDs.

(For 60Hz mode, not 120Hz mode)
Unfortunately the 60Hz BFI feature of LG C1 OLED is blurrier than the BFI feature in LG CX OLED.
LG CX OLED BFI Maximum = ~4ms MPRT = 75% less motion blur sample-hold 60Hz
LG C1 OLED BFI Maximum = ~8ms MPRT = 50% less blur than sample-hold 60Hz

In comparision, at 0.3ms MPRT both the Valve Index VR LCD as well as the Oculus Quest 2 VR LCD -- these headset has a perfectly-measured 98.3% less motion blur than a sample-and-hold 60Hz OLED with BFI disabled calculated as (1.0 - (0.3 / 16.7)).

0.3ms MPRT = 0.3 pixels of blur per 1000 pixels/sec panning
16.7ms MPRT = 16.7 pixels blur per 1000 pixels/sec panning

Even with BFI enabled, Quest 2 still has more than 10x less motion blur than the best LG CX OLED (0.3ms vs 4ms MPRT), and more than 20x less motion blur than your LG C1 OLED (0.3ms vs 8ms MPRT). I'm sorry to be the bearer of bad OLED news from a motion resolution perspective. That said, they are much cleaner in ghosting/coronas/pixel response.

However, things magically change with the world's best-strobe-tuned LCDs when all the LCD pixel garbage is completely hidden in dark. There's a 16.7ms time-budget for hiding LCD GtG at 60Hz. If you strobe at only 0.3ms, there's still 16.4ms of darkness to hide LCD GtG. You do have to hide LCD scanout (high speed videos of LCD scanout), so that's why I use the refresh rate headroom trick, to speed this part up, e.g. 60Hz refresh cycles scanned out in 1/240sec. Then you've got 3/4ths of 1/60sec to wait-out slow LCD GtG in total darkness. If you can hide 100% of LCD GtG artifacts in total darkness, or at least 99.9% (pushing artifacts below human visible noisefloor) for all pixel color combinations on the entire GtG heatmap -- then the 0.3ms MPRT shows perfectly better-than-CRT 0.3ms. Like the VR LCDs.

Strobe benchmarks are totally different from visible-GtG benchmarks, because strobe is a just a mere game of hiding GtG -- and sometimes it's done badly, and sometimes it's done virtually perfectly (the 1% cream of crop LCDs). The theoretical clarity of LCDs is now infinite once GtG100% is perfectly hidden in VBI. This happened recently, and the limitation of motion clarity of LCDs is merely simply how brightly & briefly the backlight can be flashed. One can even use a water-cooled backlight to strobe 10,000 nits for 0.1ms, to even be better than short-persistence phosphor CRTs, which still has green-phosphor ghosting on blacks, which the top 1% strobed LCDs do not have. It's very hard still, but the entire real world GtG-100% heatmap (65280 pixel color combos in 8-bit, excluding the no-operation changes, 65536-256) finally became perfect below human visible error margins on certain best-1% strobed LCDs. When used with refresh rate headroom and QFT tricks, LCD GtG finally sped up recently to be successfully hidden in VBI, which was the magical thing allowing LCDs to have unbounded motion clarity ability (beating CRTs in motion resolution).
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