LightBoost; say good bye to your CRT

[KaareKanin]

First a small disclaimer, I did a search for lightboost and found it mentioned a few times, but nothing like a whole topic devoted to it. If this turns out to be wrong, just abandon topic

 

So I read an article about something called LightBoost, basically it's an technology nvidia developed to be used with their 3d technology. What it does is that it makes the backlight in your display strobe in sync with the refreshrate of the display. This does a few useful things for 3d-gaming, but it can be used for 2d gaming as well. 

 

According to this site:

http://www.blurbusters.com/faq/60vs120vslb/

it makes the hold between refreshrates substantially lower, resulting in far less unwanted motion blur, making the clarity of pictures comparable to that of CRT displays. 

 

Not all displays support this and it's only officially supported by nvidia for 3d-operations, but there are ways

[adotkdotjh]

Interesting. I hope manufactures would look into it more. Imagine LCDs without motion blur. 

 

That being said, if you still regularly use CRT, i have mad respect for you for putting up with that heavy-bulky-low resolution-heater for the sole pursuit of no motion blur.  

[mdrejhon]

First a small disclaimer, I did a search for lightboost and found it mentioned a few times, but nothing like a whole topic devoted to it. If this turns out to be wrong, just abandon topic

 

There's a very popular thread on HardForum and OCN Forums with over 100,000 views, on this topic.

Also, LightBoost has garnered media coverage on many sites including TFTCentral, AnandTech, ArsTechnica, and many others.

John Carmack (iD Software) and Michael Abrash (Valve Software) also talked about the topic of strobe backlights recently.  For those not aware, LightBoost is a strobe backlight that flashes only on fully refreshed frames (keeping pixel transitions in the dark between refreshes). 

 

Not all displays support this and it's only officially supported by nvidia for 3d-operations, but there are ways

 

Yeah, ToastyX Strobelight makes it easy to turn ON/OFF LightBoost via a keypress, independently of nVidia.  

[GoodBytes]

The problem is that the LCD monitor feels like a shitty CRT monitor, with all the flickering.

And a lot of people are sensitive to that, especially if you use the computer for long hours... like to do actual work.

 

Moreover, you are using a 120Hz monitor.. but only get 60Hz when Light boost is enabled, making the advantage of owning a 120Hz monitor worthless.

Money could have been spend on a high consumer grade IPS panel, which will makes games much better looking, enjoyable, and appreciate a lot better the art style, than a hint reduction of visible motion blur (unless you got had, with a 120Hz TN panel, which is really an 60Hz one overclocked to 120Hz).

[KaareKanin]

The problem is that the LCD monitor feels like a shitty CRT monitor, with all the flickering.

And a lot of people are sensitive to that, especially if you use the computer for long hours... like to do actual work.

 

Moreover, you are using a 120Hz monitor.. but only get 60Hz when Light boost is enabled, making the advantage of owning a 120Hz monitor worthless.

Money could have been spend on a high consumer grade IPS panel, which will makes games much better looking, enjoyable, and appreciate a lot better the art style, than a hint reduction of visible motion blur (unless you got had, with a 120Hz TN panel, which is really an 60Hz one overclocked to 120Hz).

 

I didn't know it lowered the refreshrate... Why it would do that makes no sense to me :-/ (I get why this would happen when using 3D but not in 2D)

[GoodBytes]

Well from my understanding it puts a black screen at a 60Hz interval.

[A/C]

http://www.techngaming.com/home/guide/tips/updated-eliminate-motion-blur-while-gaming-with-nvidia-lightboost-r485

http://www.overclock.net/t/1339384/zero-motion-blur-lcd-nvidia-lightboost-hack-looks-like-crt-looks-like-480hz/960

 

U jelly IPS panels?

[GoodBytes]

Well I don't know, I am pretty happy with the results I have in term of response time compared to a 144Hz monitor with Light Boost:

(From TFTCentral)

And based on Dell, my U2410, is suppose to be 6ms response time. I can't wait until faster IPS panel comes along.

And I get enjoy to absolutely stunning.. no... I take it back... seizure making visuals due its awesomeness, and its calibrated sRGB and Adobe RGB profiles provided out of the box with report. And 0 back light bleeding, let alone a non flickering monitor due to Light Boost.

If that's what you are insinuating as I am "jelly" about LightBoost, I can assure you I am not. Heck I even have component and composite connector, I can plug an old school game console, or even VCR if I feel like being retro for a moment. And with Side by Side Picture in Picture, I can can play a console game (any), on one side of my screen, and the other I can have something else, like my desktop. Or I can have my laptop and desktop. or TV and desktop, or well any combination you want, pretty much..

U Jelly TN panels?

[A/C]

Well I don't know, I am pretty happy with the results I have in term of response time compared to a 144Hz monitor with Light Boost:

(From TFTCentral)

And based on Dell, my U2410, is suppose to be 6ms response time. I can't wait until faster IPS panel comes along.

And I get enjoy to absolutely stunning.. no... I take it back... seizure making visuals due its awesomeness, and its calibrated sRGB and Adobe RGB profiles provided out of the box with report. And 0 back light bleeding, let alone a non flickering monitor due to Light Boost.

If that's what you are insinuating as I am "jelly" about LightBoost, I can assure you I am not. Heck I even have component and composite connector, I can plug an old school game console, or even VCR if I feel like being retro for a moment. And with Side by Side Picture in Picture, I can can play a console game (any), on one side of my screen, and the other I can have something else, like my desktop. Or I can have my laptop and desktop. or TV and desktop, or well any combination you want, pretty much..

U Jelly TN panels?

 

Yeah yeah, I've read that story long ago. Lightboost hack is king in FPS, that's what I'm saying. Everywhere else, it's IPS. But I use the monitor for FPS, hence TN panels are more useful for me and people like me. And 3d is just a bonus sometimes.

 

Hit a nerve did I?

[GoodBytes]

I play FPS games, and IPS all the way. The graphics looks better, as you see them properly.

I am not a competitive hardcore FPS player, though.

[KaareKanin]

I play FPS games, and IPS all the way. The graphics looks better, as you see them properly.

I am not a competitive hardcore FPS player, though.

 

From my understanding, it's mainly those guys who use CRTs nowadays Either way, from what I've heard, this "hack" or whatever it should be called, will significantly improve the experience over not using it.

 

Another thing: Is there any reason it wouldn't work with an IPS-screen? Aren't there any IPS-displays that support nvidias 3D technology?

[A/C]

Yes, and no, you need the backlight strobe if I'm right, and the IPS panels don't have them...

 

Could you post some?

[GoodBytes]

From my understanding, it's mainly those guys who use CRTs nowadays Either way, from what I've heard, this "hack" or whatever it should be called, will significantly improve the experience over not using it.

 

Another thing: Is there any reason it wouldn't work with an IPS-screen? Aren't there any IPS-displays that support nvidias 3D technology?

IPS panel can only go at 60Hz, as you need a monitor panel where the ACTUAL response time (not the B.S measurement given by manufacture), is ~8ms to reach 120Hz. So, they can't do stereoscopic 3D with active shutter glasses (Nvidia 3D glasses).

While IPS panels is getting faster and faster each generation, without image/color quality loss. It just a mater of time before we see true 120Hz IPS panels. Maybe in 5 years from now?

Because it does support 120Hz, it can't support LightBoost.

[KaareKanin]

IPS panel can only go at 60Hz, as you need a monitor panel where the ACTUAL response time (not the B.S measurement given by manufacture), is ~8ms to reach 120Hz. So, they can't do stereoscopic 3D with active shutter glasses (Nvidia 3D glasses).

While IPS panels is getting faster and faster each generation, without image/color quality loss. It just a mater of time before we see true 120Hz IPS panels. Maybe in 5 years from now?

Because it does support 120Hz, it can't support LightBoost.

 

I had no idea there weren't any 120Hz IPS displays

[GoodBytes]

[A/C]

False, there are already "3d IPS displays", they just can't do lightboost

https://www.asus.com/Monitors_Projectors/VG23AH/

[mdrejhon]

The problem is that the LCD monitor feels like a shitty CRT monitor, with all the flickering.

And a lot of people are sensitive to that, especially if you use the computer for long hours... like to do actual work.

 

LightBoost has the same amount of flicker as a 120Hz CRT.  LightBoost doesn't lower the framerate to 60Hz, it's still 120Hz.

It is not the same thing as PWM dimming (see LCD Motion Artifacts 101).  There are plenty of good testimonials from CRT users.

 

If you don't like LIghtBoost, there is also the 120Hz overclockable IPS/PLS 1440p monitors, as well as some new HDTV's supporting true 120Hz from a PC.   Computer programming certainly is better from a 1440p monitor.

 

 

Money could have been spend on a high consumer grade IPS panel, which will makes games much better looking, enjoyable, and appreciate a lot better the art style, than a hint reduction of visible motion blur (unless you got had, with a 120Hz TN panel, which is really an 60Hz one overclocked to 120Hz).

 

All 60Hz LCD's are 30Hz LCD's overclocked to 60Hz.

 

Presume you meant the last sentence sarcastically... 

But on a more serious note, for a long time in the past, many LCD's were never meant to do 60Hz very well -- more than ten years ago when LCD monitors were still new, there was very slow 33ms LCD's that streaked all over the place when trying to do 60Hz (multiple frames blurred into each other).   That's almost like really overclocking an LCD, since 33ms is more than 1/60sec, arguably moreso of an overclocking technicality at the scientific level, than within many 120Hz monitors today.  

[GoodBytes]

If you have flickering.. you have reduce Hz.. so the monitor is 60Hz. Simple.

 

All 60Hz LCD's are 30Hz LCD's overclocked to 60Hz.

 

What? No I was referring to monitor like this one (from TFTCentral):

As you can see, this has HORRIBLE actual response time, for 120Hz monitor (BenQ claimed 1ms response time)

The monitor is long discontinued, and so far, I don't think they are any awful like this one anymore.

The above, as you can see, even for a 60Hz cheapo TN is very bad. This indicating that perhaps the monitor was really a 60Hz one, and they overclocked it to 120Hz.

[mdrejhon]

What? No I was referring to monitor like this one (from TFTCentral):

As you can see, this has HORRIBLE actual response time, for 120Hz monitor (BenQ claimed 1ms response time)

The monitor is long discontinued, and so far, I don't think they are any awful like this one anymore.

The above, as you can see, even for a 60Hz cheapo TN is very bad. This indicating that perhaps the monitor was really a 60Hz one, and they overclocked it to 120Hz.

 

Stationary cameras don't properly capture what human eye tracking does.  It's like staring stationary at the middle of the screen while the racecar scrolls past.  So it's not WYSIWYG.  You need a pursuit camera setup (e.g. MotionMaster Display Measurement Kit, or something similar).  The photos at LCD Motion Artifacts 101 [True WYSIWYG] as well as PHOTOS: 60Hz vs 120Hz vs LightBoost [True WYSIWYG] were taken with a pursuit camera.  Private messages between myself and Simon Baker (owner of TFTCentral) said they liked & agreed with the pursuit camera approach, though it's quite hard for a blogger to do, though there is now a new blogger-accessible instructions for pursuit camera photography, published here in this page.   Eventually, some reviewer sites may begin using this type of approach to capture pictures more representative of what the human eye sees.

 

Take a look at eye-tracking animation at www.testufo.com/#test=eyetracking (View in Chrome, IE10+, or FF24 Beta).  This is a cause of motion blur that's not caused by pixel transition speed, and this is more of a dominant cause of motion blur nowadays, than pixel transition speeds.  If you still don't understand how eye tracking creates motion blur, see Why Do Some OLED's Have Motion Blur?, and then also read the science papers.

 

Also, see TFTCentral's Motion Blur Reduction Backlights Including LightBoost.  I gave some input (see my name at the top of TFTCentral). TFTCentral also explains sample-and-hold in this page, and they also said they liked LightBoost:

 

Conclusion

 

We went into this article with an open, but quite sceptical mind about motion blur reduction backlights. We'd tested several scanning backlight systems in the past and never been very impressed at all. We've talked in this article about the different techniques used and what a good scanning backlight system would need to look like to offer decent results, and older attempts in the desktop monitor market had certainly never really delivered in our opinion.

 

We expected similar mixed results from the new LightBoost method which we'd read about with interest. We weren't expecting much but all in all we were suitably impressed to be honest with the performance we saw. There's a few limitations with the technology in its early days at the moment (limited brightness and possible flicker mainly), but there are certainly some big benefits for anyone wanting to improve their gaming experience on an LCD screen. We were very impressed by the improvements it brought to moving images, providing greatly reduced motion blur in practice and making eye-tracking much clearer and easier. This brings obvious advantages for any kind of gaming or fast moving content, where the hold-type nature of LCD's has really been a problem for manufacturers for a long time. We always recommend fast response time screens for high end gaming, preferably with 120Hz+ refresh rates to bring about obvious smoothness and frame rate benefits. The fact that many of these screens support stroboscopic backlights is an added bonus and really does add another level of performance improvements. If you've got a LightBoost capable monitor, give this method a go as in our opinion it really is worth it.

[GoodBytes]

I don't care what the human eye can see. The human eye sees the reality. Our visual cortex does the heavy processing and image manipulation to fix errors to try for teh rest of the brain to make sense of the world. And this is the core reason why:

 

 -> Human eye can't see 16.7 million colors, so anything better, let alone at, is not needed -> FALSE! Despite several studies that was done, the studies were flawed in it's execution. The research basically did (varying depending on it, but essentially the same): Here is a blue cardboard, and here is another blue cardboard..Are they the same blue? They ask the subject. The answer is no, and they go like this for a set of colors, and end up that "Oh! we don't see many colors in reality!". Well this is bogus, while we can't recognize these colors like this (let alone we have no idea if the printer actually printed the supposed color on the cardboard correctly), we can identity the color shift in an overall picture. Drop the color amount in your picture editor, and you'll see that you have less colors, and the image is ugly. The human eye can capture several billion even possibly trillions of colors.

 

 -> Human eye can't see flicking at 75Hz. So buying a monitor (CRTs back then) higher than that was a waste of money -> Yet people have headaches even at 100Hz, and flickering amount can't be defined by just "75Hz", as you have the phosphor that retain the light as a big factor. What I mean, is that: if the phosphor layer is thin and sucky, it won't retain light so you'll have heavy flickering. If the phosphor layer was thick and high grade, you will have significantly less flickering. But you only get the good stuff, in the higher end (more expensive) CRT monitor, which can also do higher refresh rate. So buying a better monitor is not a waste of money. While I would agree that at this rate you wont' see flickering on some CRT monitors. You still sense something is wrong, and many/most people you have a headache after a while. So, FALSE!

 

-> Inexpensive earphone is what people needs to get, anything higher is a placebo effect, as the human ear can't hear the frequencies of teh better headphones.... I don't think I need to explain how wrong this statement is.

 

And there is more... That is why it is important to question things, and not take it as is.

 

So no. You are wrong. Sadly for your wallet and mine, our eyes are too good, and while we sometimes can't put our finger on it to pin point what is wrong with what we are seeing, as our visual cortex of Mr.Brain does all the corrections, we know it's wrong.

 

So in conclusion, pursuit camera only gets you crap visuals.

[mdrejhon]

Buddy, I know what you're saying.

But, we're both correct -- you misunderstood me.

 

So in conclusion, pursuit camera only gets you crap visuals.

 

It's not for visuals; it's for more accurately photographically comparing motion between different displays in a format that's *closer* to what the human eye saw, *than* a static photograph.  As in motion blur, motion artifacts, etc.

 

Here are example pursuit camera photographs, that more properly demonstrates the purpose of pursuit camera photographs:
During motion of framerate matching refresh rate, the below photos are of www.testufo.com/ghosting -- View that webpage in a VSYNC-capable web browser (make sure it runs at full framerate), and see the remarkable similiarity of what you saw with your human eyes, to the photos below, as an example.

 

  60 Hz LCD 

 

  120Hz LCD -- 50% less motion blur than 60Hz 

 

  LightBoost 

 

A great example is running ToastyX Strobelight Utility (a new easy LightBoost utility) on a LightBoost LCD, and then turning ON/OFF LightBoost (Control+Alt+Plus and Control+Alt+Minus) while in the middle of viewing www.testufo.com/ghosting in a stable/fluid web browser -- every human who did this, says the photos agree quite accurately with what they saw.  Some minor variances between monitors (e.g. IPS vs TN vs VA) but always nearest-matched the correct photo of one of the above, since the sample-and-hold effect is the dominant factor of motion blur in today's monitors.  People sensitive to motion blur have confirmed that they see the same benefits in their game (especially when the game is running at framerate matching refreshrate). Obviously, you nee framerate matching refresh rates, to have the maximum possible fluidity on the display (best case scenario).

 

I don't care what the human eye can see. The human eye sees the reality. Our visual cortex does the heavy processing and image manipulation to fix errors to try for teh rest of the brain to make sense of the world. And this is the core reason why:

 

No disagreement there.  But you missed the point, again.

 

Scientists already know why motion blur happens with flickerfree displays -- it's called the sample-and-hold effect.  When your eyes are tracking moving objects on a flickerfree display, the static frames means your eyes are in a different position at the beginning of a refresh than at the end of a refresh.  That means the frames are blurred across your retinas.   The amount of motion blur is directly proportonal to the length of the visible part of the refresh.   Mathematically, 1ms of persistence translates to 1 pixel of tracking-based motion blur for 1000 pixels/sec motion (1 pixel per millisecond).   The only way to reduce this type of motion blur is to either add flicker (CRT / plasma / black frames / strobe backlight) or to add extra intermediate frames (interpolation or genuine frames).  Both methods shorten the static period of a frame.  

 

The Average User doesn't understand how the "sample-and-hold effect" works (the educational motion tests at www.testufo.com/eyetracking and www.testufo.com/blackframes does help to an extent).  However, it's all well-established science and explains how it interacts with vision.  Here are scientific references that show the well-known vision science of sample-and-hold:

 

List of Science Papers

 

What is needed in LCD panels to achieve CRT-like motion portrayal?
by A. A. S. Sluyterman (Journal of the SID 14/8, pp. 681-686, 2006.)
This is an older 2006 paper that explains how scanning backlight can help bypass the "hold effect". 

 

Temporal Rate Conversion (Microsoft Research)
Information about frame rate conversion, that also explains how eye tracking produces perceived motion blur on a sample-and-hold display, including explanatory diagrams.

Correlation between perceived motion blur and MPRT measurement
by J. Someya (SID05 Digest, pp. 10181021, 2005.)
Covers the relationship between human perceived motion blur versus Motion Picture Response Time (MPRT) of the display. This also accounts for motion blur caused by eye tracking on a sample-and-hold display, a separate factor than pixel persistence.

Frame Rate conversion in the HD Era
by Oliver Erdler (Stuttgart Technology Center, EuTEC, Sony Germany, 2008)
Page 4 has very useful motion blur diagrams, comparing sample-and-hold versus impulse-driven displays.

Perceptually-motivated Real-time Temporal Upsampling of 3D Content for High-refresh-rate Displays
by Piotr Didyk, Elmar Eisemann, Tobias Ritschel, Karol Myszkowski, Hans-Peter Seidel
(EUROGRAPHICS 2010 by guest editors T. Akenine-Mller and M. Zwicker)
Section 3. Perception of Displays (and Figure 1) explains how LCD pixel response blur can be separate from hold-type (eye-tracking) motion blur.

Display-induced motion artifacts
by Johan Bergquist (Display and Optics Research, Nokia-Japan, 2007)
Many excellent graphics and diagrams of motion blur, including impulse-driven and sample-and-hold examples.

 

 

....Anyway it is kind of nonsensical for you to say that I am wrong when I'm just quoting facts, all from pre-established vision research.  It may be a matter of "diminishing points of returns" (Certainly a legitimate wallet concern ), but I'm certainly not scientifically wrong here -- you were saying "while we sometimes can't put our finger on it to pin point what is wrong with what we are seeing", you didn't realize that there are already established science papers over this matter that explains a lot of sample-and-hold already.

 

In fact, speaking of "wallets", it's already very profitable for ASUS (an ASUS rep mentions its popularity in their NewEgg YouTube).  The VG248QE is one of ASUS' better selling monitors, and very few monitors have over 100 Amazon reviews.  Hit Control+F while viewing that page, and search for word "LightBoost"; you'll see numerous users acclaim about it for themselves in those customer reviews.   Now Sony(click) and Eizo(click) are following suit with strobe backlights similar to LightBoost, and making them easier to turn on than nVidia's own LightBoost (nVidia originally force-bundled the LightBoost strobe backlight feature for 3D vision, and made it hard to enable without a 3D vision kit).   Blur Busters does get lots of visitors a week now (tens of thousands).  Motion-blur sensitive people exist in numbers big enough to create such demand.   Certainly not "millions of people" demand, but certainly big enough for quite a number of parties who want to get closer to the Holodeck experience. 

 

Sincerely,

Mark Rejhon

Owner of Blur Busters / TestUFO 

(Frequent collaborator with review sites including Adam of pcmonitors, Simon of TFTCentral, etc).

[GoodBytes]

It's ok. Monster Cable says their own Beats By Dr.Dre products are best headphones in the world. I am sure they are correct.

Not my money. I prefer to spend my monitor on a decent monitor than on Tylenol.

[mdrejhon]

Not my money. I prefer to spend my monitor on a decent monitor than on Tylenol.

 

Not a problem.  This is true -- LightBoost isn't good for people who hated CRT's (even at 120Hz).

 

LightBoost looks like a 120Hz CRT with 120Hz flicker. LightBoost isn't for people who get CRT eyestrain.  For most people, there's no difference in eyestrain so they just enjoy the blur reduction.  That said, some motion-blur-sensitive people like me get less eyestrain with LightBoost than without (Vega, l88tbastard, me, etc)  

 

The LightBoost FAQ has both entries: 

"Why Does LightBoost Have MORE Eyestrain?" (people who hated CRT)

"Why Does LightBoost Have LESS Eyestrain?" (people who loved high-refresh CRT).

 

Some of us get even get eyestrain from motion blur. Some get eyestrain from PWM but not from CRT or LightBoost. This is because for certain people, the eyestrain actually didn't come from flicker, but came from ugly looking motion blur that's painful to focus on (PWM motion artifacts makes motion blur ugly -- if your monitor has PWM dimming, view www.testufo.com/ghosting while brightness is set to minimum.  You'll notice what you are seeing, closely resembles the pursuit camera photograph)

 

As a very rough, general rule of thumb:

You got eyestrain with CRT but not LCD -> LightBoost probably will give eyestrain.

You don't get eyestrain with either CRT or LCD -> LightBoost is roughly equivalent. 

You get eyestrain with PWM dimming, but never with CRT -> LightBoost may actually reduce eyestrain.

 

It's just some interesting observations (from many user reports) worth adding.  What's important for the future, is a strobe backlight (that can easily be turned ON/OFF via monitor menus) gets added to more monitors.  Especially IPS and VA, rather than TN.

[GoodBytes]

I love CRT. I am big fan of them. You clearly know nothing about them, else you would know that decent CRT monitor didn't flicker, due to the high grade and thick layer of phosphor using inside. This is basic knowledge.

Light boost is a cheap excuse. Nothing more.

But you are right, why do things right? Let's make money on people ignorance, and cheap effects, instead of pushing panel technologies by spending millions in R&D, to get true low response time.

[mdrejhon]

I love CRT. I am big fan of them. You clearly know nothing about them, else you would know that decent CRT monitor didn't flicker, due to the high grade and thick layer of phosphor using inside. This is basic knowledge.

 

To the contrary, I'm very familiar with CRT's.  

 

I have owned CRT's for a very long time, and owned a CRT projector with a 92" projection screen (Photos from 15 years ago).  I am familiar with CRT phosphor decay, medium-persistence CRT phosphor and short-persistence CRT phosphor, and how they relate to motion blur/ghosting (especially the green color component), too as well.  If you want to dispute this, I will reply with photographs of my CRT work too as well.  I used to work in the home theater industry on high-end $10,000 boxes (I'm the inventor of the world's first public open-source 3:2 deinterlacing algorithm).

 

If you're going to choose that definition of "flicker", then LightBoost doesn't flicker either.  I can't see LightBoost flicker either.  Most LightBoost users cannot either.

 

We can go into semantics such as sensitivity to the flicker, flicker duty cycle, the curve of how it goes from bright-to-dark (phosphor decay versus strobe backlight).  It all affects the appearance of ghosting and motion blur.  I am far more familiar scientifically than you are, in how the illumination-and-decay cycle of various technologies interacts with tracking-based motion blurring.  CRT's often go mostly dark almost immediately after illumination (with a little bit of phosphor decay afterglow).  You've probably no doubt seen several high speed videos of CRT's such as this one, or this one.  They all show that each point on a CRT flickers at one flash per refresh.  At least by the scientific definition of flicker, such as the definition of the word "flicker" used in this lighting study paper.  

 

If you define "flicker" as being something universally human detectable, then you're theoretically right.  But since many of us don't see LightBoost flicker, what you said isn't scientifically backed.  If you can't see flicker on a 120Hz CRT, you can't see flicker on a 120Hz LightBoost either (especially since there's no PWM artifacts at one flash per display point per refresh).  No doubt that the CRT decays more slowly than the more abrupt off-cycle of a strobe backlight (though some of them use capacitor-decay to soften the decay), but apparently, this isn't being noticed by the vast majority of LightBoost users.  The (unseen) flicker of a CRT is what causes the low amount of motion blur of a CRT.  Even a 200Hz Mitsubishi Diamonvision still flickers, under a high speed camera (Even if you can't see the flicker, all CRTs flickers under high speed camera.  It doesn't matter if we can't see the flicker or not -- the short persistence (aka flicker) is what is eliminating motion blur on CRT.  For this thread, we're not talking about the color quality here at the moment, but the motion clarity.  

 

Yes, the curves of the on-to-off cycle of a phosphor is softer than a strobe backlight.  Yes, it might mean that strobing might be detectable at slightly higher frequencies if the falloffs are harsher.  (e.g. 75Hz versus 85Hz human flicker sensitivity -- e.g. like the difference between short-persistence CRT phosphor and long-persistence CRT phosphor).   But that's not the point.  Short-persistence CRT have very fast light-output falloffs, sometimes faster than the falloff of a strobe backlight!  (I've seen it with my oscilloscope).  The point here, is that all CRT's brighten-and-darken each dot (aka flicker) even if the flicker is unseen, and that's the cause of the excellent motion resolution.  The shorter persistence phosphors (which doesn't necessarily have better color quality, but we're not talking color quality) has less motion blur and ghosting during fast motion. 

 

I'm familiar with all kinds of artifacts such as scan skew effects (e.g. the tilting of the line at www.testufo.com/blurtrail in full screen mode) to things like green ghosting (varies on CRT and how fast its phosphor decays), the quality and speed of different CRT phosphor chemical formulations, as well as how the refresh rate interacts with frame rate, on CRT's, versus plasmas, versus LCD's.  Very few people understand as well as I do, the the interaction between a display's refreshing behavior and the amount of motion blur that the human eyes sees.

 

It's already scientifically proven that the dark periods between flickers, leads to CRT's excellent motion resolution.  Longer persistence CRT's have more motion blur, and short persistence CRT's have less motion blur.  Regardless of refresh rate.   CRT 60fps @ 60Hz has less motion blur than a non-strobed LCD 120fps @ 120hz.  Even you can agree with that too.  

 

Instant-pixel-transition displays can have motion blur (caused by sample-and-hold).  So making pixel transitions infinitely fast won't help motion blur, because transition time isn't true low response time.  See Why Do Some OLED's Have Motion Blur?   

 

True response time is not caused by transition time, but by the visibility time (persistence).  True low response time is the "persistence"; the "hold time"; the "pixel visibility time" (sometimes interchangeably used).  This is known to some display researchers as Moving Picture Response Time (MPRT) in scientific papers, rather than the GtG transition time.  Manufacturers have a hard time lowering this value, so they instead advertise the much easier pixel transition time (GtG) which does not accurately represent motion blur.  True low response time is the hold time; the pixel visibility time; also described as "persistence" as already written in scientific papers.   Sometimes we're using different terminology, I try to simplify the complex stuff into the easy-to-read stuff for the mass audience.   So you and I are already talking about exactly the same thing (true low response time) without realizing it.

 

Someday we can dream about the infinite-framerate infinite-resolution Holodeck, that has no motion blur, no flicker, no strobing, and we can all live in harmony.  But until then, finite-refresh-rate displays (CRT, LCD and otherwise) will always have human-noticeable compromises.  It'll be a very long time before we get display that has 5-sigma indistinguishable from real-life.