Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

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.
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HyperSlayer72
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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by HyperSlayer72 » 27 Mar 2020, 16:20

Chief Blur Buster wrote:
27 Mar 2020, 16:07
HyperSlayer72 wrote:
27 Mar 2020, 16:03
Considering what you said about VA panels what do we have look forward to in the future regarding low persistence low black level displays? I've been curious for a while whether miniled backlight technology by chance have response times fast enough to be paired with high hz TN or IPS monitors to give them true blacks. Is that a possibility or do we have to wait for another technology?
OLED and MiniLED can have response times fast enough. MiniLED even more so. The problem is in the driver electronics, which needs to be customized -- e.g. Custom 960Hz Scan Electronics.

There is a lot of complexities. Just because fast pixel response exists, does not mean that the driver electronics are fast enough to keep up. LCD is already capable of 1000 Hz refresh rates, but driver electronics aren't keeping up. I expect the first affordable 1000Hz display to be an LCD. But the best high-Hz quality will come from MiniLED once they receive similar driver electronics.

Before then, a possible good compromise is a MiniLED HDR scanning backlight with a fast LCD that can has relatively thin GtG fade zones outside the scanning backlight internal lightbleed zone (to avoid scanning backlight crosstalk). More info about GtG fade zones at www.blurbusters.com/scanout (High speed videos) and scanning backlights at www.blurbusters.com/faq/creating-strobe-backlight (Engineering article).
This might be getting a bit beyond me but it still very much interests me nonetheless. Especially what you said regarding Driver electronics being a limiting factor. Do you have more sources or info to share on what exactly is holding back driver electronics? Ive often wondered what evolution's have taken place that reduce the hardware/processing latency in high hz displays.

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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by HyperSlayer72 » 27 Mar 2020, 16:33

Im worried about how long we will have to wait to see miniled paired with TN and IPS at more reasonable resolutions and prices. Asus seems to be focused on using miniled on their extreme high end which is all 27in+ 4K stuff.

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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by Chief Blur Buster » 27 Mar 2020, 17:28

About GtG slowing down when you try to refresh more frequently....
HyperSlayer72 wrote:
27 Mar 2020, 16:20
This might be getting a bit beyond me but it still very much interests me nonetheless. Especially what you said regarding Driver electronics being a limiting factor. Do you have more sources or info to share on what exactly is holding back driver electronics? Ive often wondered what evolution's have taken place that reduce the hardware/processing latency in high hz displays.
Metaphor: Pixels As Soccer Balls
Here are some facts:

1. Not all pixels on a screen can refresh at the same time.
2. Each pixel requires a finite amount of time to "kickstart" the pixel response.
3. Think of each pixel like separate soccer ball or football.

You see screen refreshing in high speed videos at www.blurbusters.com/scanout ... Many screens refresh only a few pixels at a time, left-to-right, top-to-bottom. Like sequencing the days of a calendar, except the calendar week is 1920 days wide (width) and 1080 weeks tall (height), but really fast.

Each pixel has to be kicked one at a time. It takes time for the player (driver electronics) to give that ball a very fast GtG kick, before moving on to the next ball.

Imagie you have 100 balls to kick. Do you kick each one of them as quickly as possible (kick more than 1 ball per second), or do you properly give you a running start to kick the ball faster? You'll spend more time kicking one ball, but you can kick that ball faster (faster GtG)

That's the problem. Speeding up the display driver can slow down pixel response in much the same "Catch-22" way. (Things like resistance, inductance, voltage ramp-up -- are metaphorically running starts to giving one soccer ball a high-velocity kick for faster GtG).

Ball-to-ball time doesn't always correspond with ball speed. However, if you're in a hurry to kick 100 soccer balls in less than one minute, they won't all be powerful kicks (fast GtG). Driver electronics needs to spend more time giving each pixel a HARD kick (Fast GtG).

Now go back and click the links, understanding that pixels are just balls to electronically kick.

Now, imagine that there are over 2 million soccer balls per 1080p refresh cycle, 144 refresh cycles per second. If we dive to semantics, each subpixel are also separate balls -- so over 6 million soccer balls per 1080p refresh cycle! You see, the LCD panel driver electronics are working hard to kick those balls as fast as possible. Fast drivers (less time per pixel) AND fast GtG (fast pixel transition) simultaneously, is very hard to achieve simultaneously. You can do one or the other, it's hard to do both. Just like for real-world soccer balls. If you're in a hurry to kick as many balls as possible, you don't have time to give each ball a running-start kick for high-velocity (fast GtG).

Also, the previous ball (or few) can still be in mid-air by the time you kick the next ball. Likewise, a previous pixel's GtG is still in progress while the display is triggering the next pixel's GtG. Consequently, this means thousands of pixels are in GtG-progress. Like thousands of mid-air balls. To the human eye, this shows up as a "fade wipe" that scrolls from top to the bottom, as a screen "fades" from one refresh to the next -- as seen in high speed videos.

Working against fast GtG is those tiny microwires (the wire grid to each pixel). Tiny wires (for higher-resolutions) means slower-responding electricity pulses than bigger wires (for low-resolutions). That makes it quite a bit harder to kick the balls (pixels) faster. Tricks such as high voltages are used but too high a voltage, and the microwires begin leaking to each other (vertical line / horizontal line streaks found on older LCDs). And so many other tricks in a scaler/TCON, and this is why Overdrive algorithms were invented for LCDs too -- to use a pixel color beyond target, to speed up pixel transitions to target color values. But there are so many issues (ghosting/coronas). Tons of side effects the industry have to whac-a-mole against each other. And it become much harder for some of them when monitors fell below $1000, given the high costs of engineering solutions -- sometimes engineering costs 10x to 100x to improve a panel by just 10% -- the last 10% of improvement is often the incredibly expensive part. At some point, a line has to be drawn and live with the compromises (such as VA dark ghosting, or IPS slower than TN, lower contrast ratios versus fast GtG, etc). That's why highest refresh rates sometimes comes with some compromises, like TN panels and the limited viewing angles...

Now do you understand the Catch-22 conundrum of fast driver + fast GtG?

Fortunately, there's a sort of a display-equivalent of Moore's Law, where refresh rates double approximately every 5-10 years, thanks to all the engineering that goes on behind the scenes.

Welcome to the refresh rate race. ;)
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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by HyperSlayer72 » 27 Mar 2020, 17:43

Never new any of this, thanks so much for the info.

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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by Chief Blur Buster » 27 Mar 2020, 18:54

HyperSlayer72 wrote:
27 Mar 2020, 17:43
Never new any of this, thanks so much for the info.
Probably time for me to write a new article about treating pixels like soccer balls. Would be a fun article!
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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by Burgz » 27 Mar 2020, 19:45

HyperSlayer72 wrote:
27 Mar 2020, 17:43
Never new any of this, thanks so much for the info.
Still no response about flicker / pwm? :c

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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by HyperSlayer72 » 27 Mar 2020, 20:00

I was also asking about pwm/dc when not using blur reduction backlights. Just normal display modes. I remember reading a thread that said pwm monitors natively have less blur than flicker free panels. It advised to stick with high hz pwm even if you planned on not using strobbing. Based on these beliefs it begs the question, why did the industry stop using pwm all together for high hz monitors. I understand making flicker free monitors for those with eyestrain concerns. But for many other buyers myself included i'd gladly take clearer motion over a "no eyestrain" feature.

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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by Chief Blur Buster » 27 Mar 2020, 20:04

Burgz wrote:
27 Mar 2020, 19:45
Still no response about flicker / pwm? :c
I cover that in separate articles already. If there is a question I have not answered, please post a new thread and send me a PM to it.

Did You Know? Motion Blur Reduction Strobe backlights are simply one-flash-per-refresh PWM. A "good kind of PWM".

First, to understand how PWM interacts with motion blur, see this simple diagram.

Image

That's why unsynchronized PWM is so bad:

Image

With PWM dimming, motion look serrated, creating eyestrain that is sometimes also unrelated to the PWM flicker. To some people, they are so sensitive, that it almost feels like a serrated knife that stabs the eyes. This is why PWM dimming is hated by many. However, single-strobe PWM (blur reduction PWM) has far less eyestrain than multi-strobe PWM (PWM dimming strobe).

That's why some people don't get eyestrain (or less strain) from blur reduction modes (at fps=Hz), but gets far more eyestrain from unsynchronized PWM dimming. Which is awful, and should not exist in a monitor.

Sure, we wish we could eliminate motion blur without PWM, but that currently requires higher frame rates at higher refresh rates. Sometimes even 240fps at 240Hz doesn't yet reduce enough motion blur (without strobing).

Some people still get eyestrain from both, but usually, blur-reduction PWM is far by the lesser of evil compared to multi-strobe PWM dimming. It's far worse than CRT 30fps @ 60Hz for some human eyes. Not everyone gets the same kind of eyestrain/fatigue from the same causes from the same display. Focus eyestrain. Motion sickness. Motion blur eyestrain. Brightness strain. Blue light. Color blindness. Etc. Everybody sees differently.

Finite-refresh-rate displays are inherently imperfect compromises, especially for some people sensitive to the artifacts that cannot be solved by most displays. You might be one of the 90%+ that is not bothered by this or that, but the other 10% or 1% are. That's one reason why some of us like strobe backlights modes (while others hate them). The imperfectness of displays is why Blur Busters continues to successfully exist. :D

References:
-- LCD Motion Artifacts 101
-- Blur Busters Law: The Amazing Journey To Future 1000Hz Monitors
(there's several flicker paragraphs halfway down. Please read this page carefully)
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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by Chief Blur Buster » 27 Mar 2020, 20:19

HyperSlayer72 wrote:
27 Mar 2020, 20:00
I was also asking about pwm/dc when not using blur reduction backlights. Just normal display modes. I remember reading a thread that said pwm monitors natively have less blur than flicker free panels. It advised to stick with high hz pwm even if you planned on not using strobbing. Based on these beliefs idea it begs the question, why did the industry stop using pwm all together for high hz monitors. I understand making flicker free monitors for those with eyestrain concerns. But for many other buyers myself included i'd gladly take clearer motion over a "no eyestrain" feature.
All strobe backlights, are automatically a PWM mode.
(A good kind of PWM)

PWM-free monitors still re-enable (a better kind of) PWM for motion blur reduction.

BFI is PWM.
Strobe is PWM.
ULMB is PWM.
LightBoost is PWM.
Aim Stabilizer is PWM
PureXP+ is PWM
DyAc is PWM

PWM stands for Pulse Width Modulation. Flashing a backlight on and off. A strobe backlight is also flashing. Except it's properly synchronized to the refresh rate.

It's only PWM-free in non-strobed mode. There is less motion blur with PWM because PWM dimming provides "accidental blur reduction" benefits. Unfortunately, other people get more pain from PWM dimming than from blur reduction benefits.

Open up a monitor menu on a GSYNC monitor that includes ULMB, and you'll see "ULMB Pulse Width", so you can adjust the size of the pulse to improve your MPRT. LightBoost 10% vs 100% is a Pulse Width Adjustment! So if you were a user of LightBoost 10%, you simply adjusted your LightBoost PWM setting.

These settings adjust the size of the pulse width in PWM:
  • NVIDIA "LIghtBoost" % setting
  • NVIDIA "ULMB Pulse Width" setting
  • BenQ "Strobe Duty" setting
  • ViewSonic "PureXP+ Levels" (Light|Normal|Extreme|Ultra)
  • Acer "VRB" Normal/Extreme
The industry simply moved to PWM-free for non-strobed modes, and healthy one-pulse-per-refresh PWM for strobed modes.

(They just don't market strobe as PWM. But strobe is same thing as PWM).

The industry never stopped using PWM
Because PWM is still mandatory for motion blur reduction -- at least until we can do strobeless blur reduction via ultrahigh refresh rates instead. They just switched from nasty multi-strobe PWM to good single-strobe PWM.

Image
  • PWM dimming uses top rows (360Hz or 480Hz PWM on a 120Hz monitor produces that)
  • PWM blur reduction uses bottom row (beautiful single pulse PWM during fps=Hz).
Strobing is PWM. PWM is stobing. It's the same thing, artifacts-wise. Whether be PWM dimming (120fps at 360Hz PWM dimming) or multi-strobing (e.g. 60fps at 120Hz LightBoost). Except blur reduction strobing is simply strobing synchronized to refresh rate. Or PWM synchronized to refresh rate. It's also why you want fps=Hz to sync your strobe rate to the frame rate, to maximize motion pleasure and minimize eyestrain from artifacts (such as duplicate images).

Marketing simply changed.

Good PWM is now labelled "motion blur reduction" by it various brand names (LightBoost, ULMB, DyAc, ELMB, PureXP, etc). So you see, a PWM-free monitor with motion blur reduction mode, STILL has PWM. Just PWM made optional.

Also, please re-read my previous reply. ;)
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Re: Could someone "school" me on motion blur by chance? Also Requesting <240hz Strobbed Photos.

Post by HyperSlayer72 » 27 Mar 2020, 20:53

Got it. I went ahead and took a look back at 144hz vs 240hz TN displays and admit that in normal display modes the 144hz VG248qe is deffinately beaten by the likes of the Nitro XF252q.

Regarding the Asus VG279QM what do you think of the 280hz strobbed photo tftcentral provided.
Image

It looks less like there is strobe crosstalk and more to me like the camera the photo was taken with doesn't have a fast enough shutter. If that's really how it looks in person that's a bit of a shame.

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