Human Vision Has Motion Blur. Why Care about Display Motion Blur?

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Human Vision Has Motion Blur. Why Care about Display Motion Blur?

Post by Chief Blur Buster » 10 May 2020, 17:26

Joel D wrote:
10 May 2020, 15:11
I see more blur in real life when I move my hand quickly in front of my face, so why would I try to fix a real organic anomaly that's part of real life ? WAIT, I don't like blurry no, but when comparing it down to these hair splitting differences, that most likely has no impact on actual real usage (watching/playing video), I really don't get the obsession there.
Motion blur is good. It is useful when we don't mind it or want it.

TL;DR: Real world doesn't force extra motion blur above-and-beyond human vision. Nearly all displays add extra blur above-and-beyond.

Researchers have confirmed that the finiteness of refresh rates creates motion blur and/or other artifactds above-and-beyond natural human vision. This is important whe you want a display to perfectly emulate a window into real life for any reason, without artifacts, without SOE, without unwanted extra blur, etc.

Our business name is Blur Busters.

There are situations where displays should not enforce more motion blur above-and-beyond natural human vision. Motion blur is more important in some contexts. For example, emulating a Holodeck requires a display not to enforce more motion blur above-and-beyond natural human vision. That's why all the good VR headsets are low-persistence. The Valve Index is 0.33ms MPRT(100%).

Also, it's relative, just like Einstein is relative. You don't see display motion blur unless you eye-track the moving objects. It's the same reason of www.testufo.com/eyetracking and www.testufo.com/persistence ....

This is because pixel visibility time is static. As your analog eyes move past, your eyes are in different positions at the beginning and ends of pixel visibilty time (equals full refresh cycle on sample-and-hold, and equals pulse width on strobed displays). This creates the additive display motion blur -- above and beyond human vision -- during good eye-tracking situations.

Many esports players do stationary-eye-gaze on crosshairs. So they don't see the blur effects directly. But if you track eyes during a smooth pan (like Super Mario scrolling or RTS panning, or Rocket League turning (no crosshairs or fixed-objects to gaze at), or reading text while scrolling on a CRT tube, or turn head while viewing VR headset = permanent continuous panning that means motion blur equals bad VR / nausea / etc). There are other users of high-Hz displays other than CS:GO esports, y'know. We are a viable business because of our anal-ness on motion artifacts, including blur.

Displays are inherently imperfect windows to motion, and we write useful articles such as The Stroboscopic Effect of Finite Frame Rate Displays, as well as Blur Busters Law: The Amazing Journey To Future 1000 Hz Displays. If you haven't read those, go ahead and read those now. Articles like these are why some manufacturers such as ASUS has a road map to 1000 Hz displays.

Yes, it might not be important to you, but it is important to others -- eliminating display motion blur made it feasible for Half Life: Alyx VR to exist -- because motion blur was one major cause of VR nausea that happened hundreds times more often than desktop monitors. Blur Busters had a small chaos-butterfly push: We convinced the Oculus Rift to go low-persistence.

Mind you, I love 24fps natural blur cinema as much as anyone, but also see the benefit of 1000fps UltraHFR video/graphics (superior to 120fps HFR).
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Re: Human Vision Has Motion Blur. Why Care about Display Motion Blur?

Post by Chief Blur Buster » 10 May 2020, 18:10

The finiteness of a refresh rate creates issues that diverges from real-life (e.g. CS:GO versus being a real solder in a real war), including the following:

Image

For more information, see The Stroboscopic Effect Of Finite-Framerate Displays.

Over the last ten years, billions of dollars have been spent, by multiple companies combined, on research to make VR mimic a Star Trek Holodeck better. No blur or stroboscopics above-and-beyond natural human vision.

Even when we reach retina screens, we might be decades away from simultaneously achieving retina resolution AND retina refresh rates at the same time. Largely because of the finiteness of refresh rates and the finiteness of frame rates. Real life has no frame rate.

To understand the difficult whac-a-mole effect that makes Blur Busters viable, understanding the Vicious Cycle Effect is a useful textbook exercise. How everything interacts -- higher resolutions, wider FOV, reduced motion blur, all amplify each others' limitations in a compounded way.

This could be important for future 4K 480Hz gaming monitors with RTX 5080 cards, as well as for retina-resolution VR. The refresh rate race is a long haul where higher Hz and reduced motion blur amplify resolution limitations and vice versa, etc. For this, we're dependant on strobing to eliminate motion blur for now due to the inability to get refresh rates high enough to eliminate motion blur with no black periods in between (1ms MPRT = requires 1000 contiguous frames to eliminate black periods in between) -- achieving 1ms MPRT is impossible to do strobelessly at current refresh rates.

What is not important in one conext to most people, may be important in another context (e.g. you may not care about display motion blur for CS:GO but you might care deeply about it when you're trying to emulate a Holodeck that there must be no additional motion blur enforced above-and-beyond natural human vision.

Sometimes the next person may find it as equally important in both contexts (desktop monitor, VR display, Holodeck display, etc.).
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Joel D
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Re: Human Vision Has Motion Blur. Why Care about Display Motion Blur?

Post by Joel D » 11 May 2020, 11:23

Thanks for the detailed focus on this subject ChiefBB ! I'm honored you used my quote for a entire thread. lol Well don't know if I'm honored or embarrassed hahaha !

So let me elaborate on why I said that because I do not want get bashed on here for raising that question.

I totally stand for reducing motion blur on any technology related visual device to the point of mimicking real life for said device. Beyond real life though, is simply not needed (IMPO).

Now admittedly for each different technology device (VR to Monitor playing games/Movies), that amount of reduction, pursuit, work, etc.. obviously will be different. But once each reaches that "look like real life" then we can stop right there, because real life is real life ! Why go beyond that ? In VR sure it might be a tougher task and therefore the need to take it further due to it causing nausea for the obvious reasons of it being a VR situation (surrounded by close up eyeglasses screen) and going to naturally make the person feel like they are really there, and nausea will be a more delicate thing there... but again, once it gets to a point where the blurring there in that situation is identical to real life, then it should be good.

monitor playing games/movies are less delicate due to we are staring at a screen and not surrounded by the screen.

Anyway, my point where this quote was taken was from the viewpoint that both them monitors we were debating IMO are so close to each other as far as blur that debating which one has less blur is really just splitting too much hairs at that point. They both outdo real life ! lol So why bicker about it anymore. That was the point. The bickering about them should move on to Color, contrast, etc.. but the ufo test comparing with them two is no longer a selling point for each one, cause they both do a great job. (that was my point)

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Re: Human Vision Has Motion Blur. Why Care about Display Motion Blur?

Post by Joel D » 11 May 2020, 11:43

Ok, ha, now that my explanation is out the way - I want to say I am fully impressed at how far BlurBusters goes to handle, help and fix these things. I had no idea. Not only in this forum, but from what I am gathering, you guys are scientifically in the industry making changes !

I am reading it all and clicking all links and reading them too. I personally want to thank you Chief (and the BB team) for this. I just learned and AM CURRENTLY learning a lot. I understand a lot more inadvertent things too just from this thread. The way you broke down the static pixel vs our analog eyes and movement totally hit home. I get WHY the unacceptable motion blur and other possible artifacts happens now.

So please keep in mind, it (blur reduction) IS important to me. And I love and dig the pursuit to perfection. I hate any artifacts that wouldn't otherwise be in my real life vision. Its just once it reaches looking like real life for said technology, why split hairs after that ? Lets perfect the next thing (color pallets, frameless, motion, etc..)

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Re: Human Vision Has Motion Blur. Why Care about Display Motion Blur?

Post by Chief Blur Buster » 11 May 2020, 11:50

You're welcome! And thanks for the compliment!

I'd have picked any quote, but I chose yours to give an in-depth answer. Many are asking the same question so this Area 51 Forum is now the new location to educate readers about why Blur Busters has to be so in-depth about display motion blur.

It might not be important to Person X for one game -- yet it's an expensive huge problem for Industry Y -- whereas there are lots in between (the common example of people who love motion blur reduction modes on desktop displays). This website first became popular because of "LightBoost" in 2012 when thousands wanted to reproduce the CRT effect -- back then, many did not believe that an LCD could ever match the motion clarity of a CRT tube -- until it actually happened (nonwithstanding other attributes like poor blacks, etc).

This thread has already been read by almost 100 lurkers in just 24 hours, so others are learning too! Probably within two year, about 10,000 people will be reading this thread.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

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