Motion resolution - does it change with 120Hz strobing?

Everything about displays and monitors. 120Hz, 144Hz, 240Hz, 4K, 1440p, input lag, display shopping, monitor purchase decisions, compare, versus, debate, and more. Questions? Just ask!
Post Reply
MonarchX
Posts: 60
Joined: 23 Feb 2014, 20:07

Motion resolution - does it change with 120Hz strobing?

Post by MonarchX » 13 Mar 2014, 18:31

I thought Blur-Busters would be the best place to answer some questions I have regarding motion resolution and light-strobing.

As far as I know 60hz LCD TV motion resolution is only 300 lines. There are 2 types of 120h/240hz resolutions on modern TVs - one kind of fake (interpolation) that creates artifacts, but the other is with light-strobing, which does improve smoothness.

How does plasma motion resolution of 880 lines at 60hz compare with 120hz TN monitors with LightBoost turned on or with Eizo Foris FG2421 Turbo 240hz light-strobing? What about regular, non-strobed 120hz?

User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Motion resolution - does it change with 120Hz strobing?

Post by Chief Blur Buster » 13 Mar 2014, 21:08

MonarchX wrote:How does plasma motion resolution of 880 lines at 60hz compare with 120hz TN monitors with LightBoost turned on or with Eizo Foris FG2421 Turbo 240hz light-strobing? What about regular, non-strobed 120hz?
Yes, motion resolution dramatically improves with strobing -- and sometimes by almost an order of magnitude in some cases.

Image
From 60Hz vs 120Hz vs LightBoost.

I prefer to measure motion resolution in "milliseconds" instead of "lines".
For reasons why: Standardizing Motion resolution: Milliseconds of Motion Blur (Not Lines of Motion Resolution).

I honestly think "lines of motion resolution" is an outdated measurement, and very testpattern-specific.
I prefer MPRT, or "milliseconds of motion blur", which is testpattern-independent & resolution-independent.
Search "MPRT" on Google Scholar.

Measuring motion blur by milliseconds, creates very simple motion blur mathematics:
1ms of persistence translates to 1 pixel of motion blurring during 1000 pixels/second framerate==refreshrate motion.
(This is what I now call "Blur Busters Law of Persistence" -- since it is repeatable observations on all strobed monitors I've tried)

For the purposes of consistency, these terminologies are equivalent on strobe backlight monitors:
persistence == strobe length == sample-and-hold-effect == amount of visibility time per refresh cycle

60Hz non-strobed = 1/60sec continuous persistence = 16.7ms = 16.7 pixels of motion blur during 1000 pixels/second
120Hz non-strobed = 1/120sec continuous persistence = 8.3ms = 8.3 pixels of motion blur during 1000 pixels/second
LightBoost 2ms = 2ms persistence = 2 pixels of motion blur during 1000 pixels/second.

LightBoost persistence is a range of 1.4ms (10%) to 2.4ms (100%)
ULMB persistence is 2.0ms
Turbo240 persistence is approximately 2.3ms
BENQ Blur Reduction persistence is 1.7ms (V1 firmware)
BENQ Blur Reduction persistence is 0.5ms through 4.0ms (V2 firmware)
(photodiode oscilloscope measurements)

View http://www.testufo.com/blurtrail on an adjustable-persistence monitor (LightBoost 10% vs 100%, or BENQ Blur Reduction 0.5ms through 4.0ms) -- adjust the persistence on the fly while seeing motion test -- and you will see the Blur Busters Law accurately in operation with your naked eye. Turbo240 is not adjustable persistence, but adjustable persistence is only available with strobed TN panels at the moment. Anyway, TestUFO motionspeed is 960 pixels/second which is extremely close to 1000 pixels/second, except it's divisible by common refresh rates (60Hz and 120Hz). However, it scales. (e.g. 1ms of persistence = 1 pixel blur at 1000pixels/sec, 2 pixels blur at 2000 pixels/sec, 4 pixels blur at 4000 pixels/sec, etc)

Copy of my old post below:
"standardizing Motion resolution: Milliseconds of Motion Blur (Not Lines of Motion Resolution)"
Mark Rejhon wrote:History:

[Edit, added to add context]
Reviewers often use "Lines of Motion Resolution", on motion test patterns based on FPD tests:
Search: "1080 lines of motion resolution" -avsforum (excludes AVSFORUM posts)
Search: "1200 lines of motion resolution" -avsforum (excludes AVSFORUM posts)

Examples:
- C|Net Review of HDTV measuring motion blur by "lines of motion resolution"
- HDGuru talks about motion blur by "lines of motion resolution"
- HDTV Magazine: Panasonic Viera touting "lines of motion resolution"
And many home theater magazines sitting here, using "lines of motion resolution" in their HDTV reviews.

Details:

Lines of motion resolution is very test-pattern specific.
- depends on speed of motion
- depends on test pattern
- depends on resolution of display (1080p versus 4K)

Milliseconds of motion resolution is test-pattern independent.
- can be measured by scientific equipment
- can be measured by human eye with certain special test patterns
- resolution independent, refresh rate independent.

Google: Moving Picture Response Time
  1. It's resolution independent.
  2. It's motion speed independent. (most displays have the same MPRT at all motion speeds and motion vectors)
  3. It's more test pattern independent.
  4. It's future proof. 1080p, 4K, 8K, VR, etc.
  5. Improvement is unbounded. It doesn't cap out at a specific value (e.g. "1200 lines of motion resolution")
  6. It easily covers the faster motion speeds often seen in video game use, an increasing use case of displays.
Easy consumer motion test patterns needs to be developed over the coming years, to discontinue the "lines of motion resolution" lingo. Even disregarding the subjectiveness problem (like Contrast), "lines of motion resolution" just simply has a far bigger superset of problems far bigger than "milliseconds of motion resolution" or "MPRT" or "moving picture response time" (which is NOT the same measurement standard as "LCD response time"). It may take time (e.g. Blu Ray becoming obsoelte), but it's time to begin migrating to a a future proof motion resolution standard.

___________________________________________________________________

I'm the author of the Blur Busters UFO Motion Tests.

I feel that motion resolution needs to be I feel it's better for motion resolution to be measured in milliseconds (MPRT), rather than motion resolution measured in "lines of motion resolution". MPRT, stands for Motion Picture Response Time. Most reviews quote a "lines of motion resolution".

With MPRT, you know that mathematically, 1 millisecond of motion blur equals 1 pixel of motion blur for every 1000 pixels/second motion. Very simple math. e.g. 4ms MPRT means you get 8 pixels of motion blur during 2000 pixels/sec motion. Apples to apples, even comparing 4K displays to 1080p displays. Note that MPRT is a different measurement than LCD pixel transitions (e.g. GtG transitions), the closest analog is the time it takes for a pixel to go BWB (black-white-black).

It would be good to see more Blu-Ray motion resolution tests to migrate to the MPRT standard, rather than "Lines of Motion Resolution". Or alternatively, motion equivalence ratios (1000 / MPRT). So a display with a true "250" measured motion equivalence ratio has about 4ms of MPRT. (1000 / 4) = 250. True measured motion equivalence numbers such as "250" is also the same amount of motion blur as a hypothetical "250fps on a perfect 250Hz sample-and-hold display", and may be more user-friendly than millisecond numbers.

That said, it's easy to convert motion equivalence ratios mathematically as 1000 / MPRT = motion equivalence ratio (MER). This is measured analog to the claimed numbers often quoted on displays (e.g. Samsung CMR 960, Motionflow XR 480, Panasonic 1600 scanning backlight) and the measured motion equivalence ratios would certainly fall short of these numbers, much like measured contrast ratios fall short of claimed numbers.

Quoting by MPRT or by MER is more apples to apples.

- Resolution independent
- Test pattern independent
- Can be measured by eye or measured by scientfic equipment
- Easy to extrapolate

With the transition from 1080p to 4K, it's time to migrate away from the archaic "Lines of motion resolution" standard, and go to the modern "milliseconds of motion resolution" (MPRT) or its simple inverse, "measured motion equivalence ratio" (MER)
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

MonarchX
Posts: 60
Joined: 23 Feb 2014, 20:07

Re: Motion resolution - does it change with 120Hz strobing?

Post by MonarchX » 14 Mar 2014, 12:26

What about actual TVs rather than monitors? Is there any information on that? I do realize this is a monitor-related forum, but I was hoping some info could be available here. I will through those links you posted.

Thank you so much!

User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Motion resolution - does it change with 120Hz strobing?

Post by Chief Blur Buster » 14 Mar 2014, 15:05

MonarchX wrote:What about actual TVs rather than monitors? Is there any information on that? I do realize this is a monitor-related forum, but I was hoping some info could be available here. I will through those links you posted.
Yep. You can do the "lines of motion resolution", such as TestUFO motion tests, on televisions. That said, most TVs do not have low-latency low-persistence modes. One exception is Sony's Motionflow Impulse -- http://www.blurbusters.com/sony-motionflow-impulse/ which is simultaneously low-latency and low-blur, by using strobing without interpolation.

That said, most TV manufacturers test using "lines of motion resolution", based on a specific test pattern. This makes it a motion blur measurement very specific to a specific Blu-Ray test pattern disc, so you can't do apples-versus-apples comparisions between televisions and monitors.

However, you can use either standard on either televisions or monitors or both, but it would be nice if the whole world eventually standardizes upon "milliseconds of motion blur". (aka "persistence measurement" rather than "GtG transition measurements"). Basically motion/persistence response measurements are very different from GtG/transition response measurements. When GtG is faster than a refresh cycle, GtG is not the cause of motion blur, while persistence is still the motion blur bottleneck. That's where strobe backlights come in, to solve -- See my other post at http://forums.blurbusters.com/viewtopic.php?f=7&t=177 for some more advanced information on understanding persistence as it relates to motion blur.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

MonarchX
Posts: 60
Joined: 23 Feb 2014, 20:07

Re: Motion resolution - does it change with 120Hz strobing?

Post by MonarchX » 16 Mar 2014, 14:06

Awesome! You are SO helpful indeed! Thank you!

That being said, I really wish we could compare today's plasma motion resolution of 1080 lines (I was wrong about 880 lines) with LightBoost/Turbo240. Plasma gets 1080 lines in 60hz, 72hz, and I think 96hz, so it has 1080 lines regardless of refresh rate. It does, however, get a slight blur from other things like phosphor lag. At the same time, IMHO, motion does seem more fluid on plasma TVs than on LightBoost monitors, even when the fastest setting is used - its easier to follow movie action on plasma than on LightBoost. Although I may be somewhat wrong because I only have Turbo240 with a slight double-image effect, but it is fast enough to follow any movie action!

User avatar
Chief Blur Buster
Site Admin
Posts: 11648
Joined: 05 Dec 2013, 15:44
Location: Toronto / Hamilton, Ontario, Canada
Contact:

Re: Motion resolution - does it change with 120Hz strobing?

Post by Chief Blur Buster » 16 Mar 2014, 17:19

MonarchX wrote:Awesome! You are SO helpful indeed! Thank you!

That being said, I really wish we could compare today's plasma motion resolution of 1080 lines (I was wrong about 880 lines) with LightBoost/Turbo240. Plasma gets 1080 lines in 60hz, 72hz, and I think 96hz, so it has 1080 lines regardless of refresh rate. It does, however, get a slight blur from other things like phosphor lag. At the same time, IMHO, motion does seem more fluid on plasma TVs than on LightBoost monitors, even when the fastest setting is used - its easier to follow movie action on plasma than on LightBoost. Although I may be somewhat wrong because I only have Turbo240 with a slight double-image effect, but it is fast enough to follow any movie action!
LightBoost has better motion resolution than plasma, but only for 120fps material. You need framerate=refreshrate=stroberate in order to maximize the motion resolution of a display! and lightboost displays behaves like a CRT limited to near 120Hz.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

Image
Forum Rules wrote:  1. Rule #1: Be Nice. This is published forum rule #1. Even To Newbies & People You Disagree With!
  2. Please report rule violations If you see a post that violates forum rules, then report the post.
  3. ALWAYS respect indie testers here. See how indies are bootstrapping Blur Busters research!

Post Reply