Motion Blur from Display Persistence, not GtG Transitions

Posted Oct 23, 2013 by in: TestUFO

John Carmack of iD Software recently talked about persistence at the G-SYNC launch.

Modern LCDs now create more motion blur from persistence (static pixel state) and not from transitions (grey-to-grey). Transitions now take only a fraction of a refresh. Pixels are mostly static for most of a refresh.

An animation at www.testufo.com/eyetracking
shows motion blur caused by persistence.

About Mark Rejhon

Also known as Chief Blur Buster. Founder of Blur Busters. Inventor of TestUFO. Read more about him on the About Mark page.

10 Comments For “Motion Blur from Display Persistence, not GtG Transitions”

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sort by:   newest | oldest | most liked
jimmy895
Member
jimmy895

I took a video of a QNIX QX2710, a PLS panel overclocked to 120Hz vs a Samsung S27A750D, a 120Hz TN panel with a low persistence mode, using a Note 3 at 4K 30fps!
https://www.youtube.com/watch?v=gG-mL3LDHQM

Like0Vote Down 
10 years 5 months ago
jimmy895
Member
jimmy895

Took another one at 720p 120fps 4x slow motion from my Note 3
https://www.youtube.com/watch?v=v8BbVBrCVW4

Like0Vote Down 
10 years 5 months ago
Mark Rejhon
Author
Mark Rejhon

That’s pretty cool.

You are already familiar with my pursuit camera work, too?
(HOWTO: Pursuit Camera with Blur Busters Motion Tests)

Like0Vote Down 
10 years 5 months ago
jimmy895
Member
jimmy895

Wow, I didn’t see this yet, a lot of great info, thanks! I attempted with my phone, but I couldn’t get anything, I even manipulated iso, ev, and monitor brightness to get 1/30sec since there’s no actual shutter control. I think it was trying to autofocus while I was pursuing, so it was just incredibly blurry. I want a DSLR!
This is a great blog, it really helped me to understand some more complex causes of perceivable blur and solutions. I recommended the Asus VG248QE to two friends, and I’m probably gonna be helping them install the G-Sync upgrade when it comes out. For now, I’m good with my cheap overclockable 1440p PLS panel and my 120Hz TN with a strobe mode. Now I’m just waiting for a 120Hz 4K OLED with G-Sync to come out! Hopefully within the next 5 years.
The screen on the Note 3 is incredible, it almost competes with my Sony HX929, the colors aren’t too accurate at all, but it’s more than good enough for watching Netflix and Youtube.
Thanks for the blog, raising awareness of the importance in reducing blur in current displays, and making good information on issues and solutions very accessible! I’m really happy that John Carmack was showing passion about low persistence and blur reduction in that short interview with Linus, since he’s the CTO of OculusVR now!

Like0Vote Down 
10 years 5 months ago
Mark Rejhon
Author
Mark Rejhon

Definitely – we’re fans of what Oculus and John Carmack is doing; raising awareness of low-persistence displays. Blur Busters was born because of a tweet reply from John Carmack more than a year ago (September 2012)

An SLR is excellent too. Ideally, make sure the SLR has a high-speed video feature so you can capture strobe backlight operation (e.g. http://www.blurbusters.com/lightboost/video. We are the world’s first blog to capture strobe backlights using high speed video, for explanation to a gaming audience. Ideally, high speed video, as well as motion tests such as http://www.testufo.com, needs to eventually become a part of any future highly technical computer monitor review of any low-persistence gaming monitors (e.g. TFTCentral, prad.de, pcmonitors.info, etc).

Alternatively, another camera to look at is the  Casio EX-FC200S (smaller) or the Casio EX-ZR200 (bigger, better quality), which can be obtained for under $250 off eBay or Amazon. It’s a pocket point and shoot, a bit larger than the average point-and-shoot, with adjustable ISO and exposure length, but has a bonus of including 480fps and 1000fps video. They do not have fixed focus like SLR’s can have, so you will have to keep the shutter button halfway depressed to focus on the screen, before pursuiting the camera according to those instructions; a different tradeoff. We use the Casio camera here at Blur Busters, since it’s a great general purpose camera for reviewing low-persistence monitors.

Also, don’t forget to try out Sony’s equivalent of LightBoost on your HX929 — Sony’s Motionflow Impulse. It’s not as good as LightBoost and it flickers a lot more (60Hz strobing), but it reduces console gaming motion blur by ~75% for your 60fps console games, without using interpolation.

We predict low-persistence monitors are going to become a lot more common in the next 12-24 months. A niche for sure, but a bigger niche.

Like0Vote Down 
10 years 5 months ago
jimmy895
Member
jimmy895

The Oculus Rift is supposed to take up 110° of vision, that made me wonder how much of my field of vision my monitor was taking up, so a while ago, I searched high and low on the internet for a way to find natural FOV, I found nothing. Several months later, I randomly found it in the description of this video
https://www.youtube.com/watch?v=87UTCEmEMzA
I just thought I should share because I was extremely happy when I found it, however, I wouldn’t be surprised if you could have figured it out on your own.

FOV Guide
http://ostermiller.org/calc/triangle.html
1. Change Angle Units to radians
2. The bottom side will be the monitor’s width
You can find the monitor’s width here http://www.displaywars.com/27-inch-16×9-vs-24-inch-16×9
3. The two other sides will be the distance from your point of view to the left side of your monitor and the right side.
4. And the Top Angle should be your FOV!

Like0Vote Down 
10 years 5 months ago
Mark Rejhon
Author
Mark Rejhon

Common monitor FOV has tended to be approximately 30 degrees, when viewing a monitor from approximately arm’s length. That’s far narrower than the Rift, obviously.

As FOV gets bigger, resolution goes higher, graphics become sharper, fast panning becomes more common, it’s becoming easier to see motion blur. It comes to the point where motion blur will become a more visible resolution bottleneck for tomorrow’s gamers, so the low-persistence progress is becoming important. There’s the dilemma: There’s no way to do low-persistence without either insanely high framerates *OR* light modulation (e.g. strobing, laser scanning, phosphor decay, plasma subfields, or otherwise modulating light intensities up/down rapidly on a strobing-like basis at one light peak per pixel per refresh). For low-persistence monitor makers, do we strobe (and occasionally bother certain human eyes), or do we use ultrahigh refresh rates/frame rates (requiring either interpolation or lots of GPU power)? Fortunately, strobing is an optional feature for LCD’s and upcoming OLED’s and we can run those in either steady-light mode (high persistence) or strobing (low persistence), at least until refresh rates hits levels high enough to eliminate the need for any form of rapid light modulation (e.g. strobing) to successfully achieve low-persistence. It’s good to see NVIDIA finally take this seriously, with G-SYNC’s upcoming low-persistence mode, and a few other manufacturers are already looking closely at this.

Like1Vote Down 
10 years 5 months ago
Ewok
Member
Ewok

So, does backlight strobing reduce this type of motion blur?

Like1Vote Down 
10 years 5 months ago
Mark Rejhon
Author
Mark Rejhon

Yes, that’s correct. Backlight strobing, such as LightBoost, reduces/eliminates this type of motion blur.
See 60Hz vs 120Hz vs LightBoost for a comparison.

Like1Vote Down 
10 years 5 months ago
wpDiscuz

Recent Content

Blur Buster Forums

Blur Busters Forums

TestUFO Motion Tests

TestUFO Motion Tests