DIY 60 Hz Backlight Strobing

I modified a $25 Dell P2212H to strobe its backlight at 60 Hz. Did I turn it into the ultimate CRT replacment? Nope! Creating a decent backlight strobing mode is much more involved than just turning the backlight off and on every 16.7 milliseconds, and for this video, I talk about why.
You can download the response time charts for the P2212H here:
www.aperturegrille.com/review...

[@BlurBusters]

Fantastic video. Fully accurate even to the standards of our advanced Area51 sections of Blur Busters. We approve of its creation.

[@ComputerTechnic217]

quiet you

[@Wolar94]

Cool video, incredibly underrated channel!!

[@Bannaja]

This video about to get BlurBusters Approved.

[@BlurBusters]

😃 ...Yes, tuning a strobe backlight is very hard. Getting GtG100% as perfect as possible in the black period between strobes.

[@Frzao]

I understood nothing, but am incredibly impressed by the results (4:35 & 15:43).

[@TheCardSlayer]

This is incredible

[@kaddasixseven3581]

really cool project. I was suprised how well it worked.

[@GFClocked]

Wow. Just wow. The fact that this was even done has blown my brain wide open.

[@jacobgirling7739]

How on earth are your videos so damn good man, like you have 3k subs and are better than like 99 percent of tech media, especially in technical detail.

[@ApertureGrille]

Thank you! Good question... :)

[@EGLVindi]

Love your work! Please never stop doing reviews! Hoping to see a 240hz review soon!

[@dafarii]

I see a a5hun video, I upvote.

[@rcdarkangel]

This was an amazing video. I had always wondered if something like this was possible but I myself lack the skills to explore it. Thank you!

[@brownvim]

I have the XG270, we need to find someone to modify the firmware or ideally viewsonic to jus enable 60hz strobed. It would be so good for consoles.

[@kmah324]

This is by far the best monitor video from 2020. Hopefully you get all the best monitors on this planet to test.

[@akkkarinn]

I'm already craving more videos, hope you're back soon!

[@ApertureGrille]

Collecting some new data right now!

[@TRHardware]

This channel entirely is pure gold! Excellent content!

[@KyoukiDotExe]

Man this was such an amazing video, geeking out over the information and knowledge I gain from watching your videos. Keep going! Seriously beating most monitor reviews, while learning much much more about how monitors work.

[@oLuii]

Daamn you're a genius! Good job!!

[@Baorihs]

New BlurBusters approved certification for 2021+ require 60Hz strobe so we will be getting some interesting new monitors in few months. But overall PC monitor market is huge disappointment compared to CRT days

[@BlurBusters]

Correct. Four monitors by two different vendors are now in the queue for the next 12 months, and a third vendor may be coming online. They won't get the logo unless they modify their firmware to 60Hz single strobe. I'm already using a prototype IPS monitor on my desk with great looking 60 Hz single strobe. It even supports a humongous VT4500 at 60Hz, which allows 4x QFT + virtually crosstalkless top/center/bottom. It may need a post-launch firmware upgrade to enable all the features. At least one may have DDC commands enabled for user strobe tuning (fingers crossed) with user accessible 100-step Overdrive Gain -- so you can temperature-compensate, since crosstalk increases/decreases with hotter/colder temperatures due to different GtG speeds from temperatures. Just like colorimeters + RGB Gains allowed advanced color tuning, we now believe improved strobe tuning should reach advanced users more widely. The problem is a lot of monitor scalers don't understand scanrate modification to reduce strobe crosstalk (either via internal scan conversion or external large vertical totals). Internal scan conversion is easy but adds lag (buffers external slow-scanrate before output to panel at high-scanrate) while external scan conversion (large vertical totals) require users to create a custom resolution. In the long term, I'd love Microsoft (end-of-VBI Present() unblock) and graphics drivers (NVIDIA, AMD) to adopt Quick Frame Transport (aka Large Vertical Totals), so it's more plug-n-play and hits two birds with one stone (reduced VSYNC latency + reduced strobe crosstalk). So that high quality strobe is possible via a simple ON/OFF setting (wthout any large-VT tweaks, and without the latency of panel built-in scan conversion.)

[@fonarte]

@@BlurBusters I would kill for a 1080p 23-25" IPS that has 60hz Strobe. I hope one of those monitors is that.

[@BlurBusters]

@@fonarte There's at least one coming this year which I am helping a manufacturer with. Keep tuned!

[@elesinalex]

I love projects like that, nice work!

[@adamcern2501]

Why can I only upvote this once... Great job!

[@CubanLegend561]

woah... this seems hype! I didn't know you could do this..!

[@BlurBusters]

We've discussed this in the Blur Busters Forums over the years. Originally, almost ten years ago, Blur Busters was www.scanningbacklight.com due to the Arduino Scanning Backlight research. One of our forum members did a 60 Hz single strobe modification of a XL2540 series.

[@pumbabeats420]

Crazy. Love your videos!

[@HyperSlayer72]

Definitely want to see more of this. I'd like to see what sort of improvement segmenting off the backlight diffusor would have. It does sound like getting this panel to strobe perfectly is a lost cause, which is why there's no harm in moving up to a slightly better model for a second project.

[@PumatSol]

Dude, you’re insane! Subscribed, please keep it up.

[@InfraredVisuals]

Sick experiment.

[@josipreponj1928]

This is very interesting. Enjoyed it alot.

[@Jojobreack324]

this video was way too good. keep up the work sir

[@ApertureGrille]

Thank you! This was one of my favorites, even though it ended up being kind of pointless. ViewSonic should be releasing their XG2431 soon-ish, and that'll do strobing at 60 Hz.

[@HumanManufactured]

your like the Doug DeMuro of monitor reviews

[@norbertromolhatatlan4364]

This is blowing my mind

[@brett20000000009]

Nice I have also hacked 60hz single strobe into a benq 240hz monitor for 60hz strobing without crosstalk high VT's are essential 60hz scanned out at 240hz speed. with VT4860 on a fast tn crosstalk is completely eliminated because of the refreshrate headroom effect. Also i'm going to try and fix the devils horn on the VG279QM and create a true vrr strobing display.

[@BlurBusters]

Yep -- this was posted in this thread: forums.blurbusters.com/viewtopic.php?f=7&t=7520#p57328

[@istahaquerahamanhasib8905]

Wow so much to learn.

[@yoked391]

gigachad video 💪

[@axaro1738]

Nice video!

[@davidjohansson1416]

YYEEEAHHH HYPE!

[@tomas352frano]

nice work... keep going...

[@TheMasterofComment]

Amazing science work! Let's be honest, a cheap budget office TN monitor from the early Led days wouldn't cut it

[@KeinZantezuken]

What a goddam nadman!

[@WaffleCake]

I don't think enough people really know how pixel response times affect image clarity in motion. I'm only here because I happened to tumble down the CRT rabbit hole thanks to Digital Foundry.

[@vrgimp8548]

I wrote a post in a thread on the blur busters forums a while back about possibly using a MEMS laser projector like the Nebra Anybeam as the source of a backlight for an LCD monitor. Either that, or using several sets of RGB laser diodes arranged from top to bottom with a combiner so you get white light. By using lasers it would allow for very short but extremely bright pulses at low power, and would help provide lower persistence than any standard LED strobe. You also would not suffer brightness loss. You could also opt to augment a standard LED strobed backlight with laser diodesto offset brightness loss.

[@NicheAsQuiche]

like a CRT but with lasers instead of electron rays?

[@GammaLyrae]

great video! The lack of 60hz strobing for desktop sized displays is a serious issue. I've resolved not to buy any new panels until something at least as performant as the XG270 comes out - with 60hz strobe support. It is a little sad that my best shots at getting this mode currently involve buying old monitors or going through the same homebrew steps you have here.

[@ApertureGrille]

I think the current recommendation is the LG CX OLED, but you're right about wanting "desktop sized" displays. Unless LG wows us at CES with an OLED monitor, we may be stuck with LCDs for the next few years at the 24" to 32" range.

[@pacman8689]

I'm waiting for the upcoming ELITE XG320U (32'' 4K 600nits) with PureXP. Now that the new BlurBusters certification requires 60Hz strobing, that monitor has become even more interesting.

[@Evan-xs8ts]

just get an oled for fast response times.

[@rajkosto]

just using transistors or mosfets to strobe after a constant voltage supply isnt safe, and you cant even do it with a constant current supply because it will freak out at the uneven usage in its current sensing, what you should actually use is a PWM-able constant current LED driver like the TPS61196 which i used to make a fully custom LED driver board for my CCFL based 3d vision monitor (which automatically retimes signal to high vtotals in 3d vision mode) which had its CCFL die out due to age: cdn.discordapp.com/attachments/751823102177968159/792543012558209044/unknown.png

[@CubanLegend561]

listen to Rajkosto 👆 he's a monitor wizard

[@brett20000000009]

I'd suggest to find a monitor that already has strobing capabilities you can easily send your own squarewave from an arduino and make it strobe at whatever rate you want.

[@rcdarkangel]

@@brett20000000009 And...where would such a gentleman start to go down such a path?

[@brett20000000009]

@@rcdarkangel I wouldn't recommend it. synchronization with refreshrate is a pain. I would just wait for the 4 blurbusters approved 60hz single strobe monitors to come out in 6mths.

[@rcdarkangel]

@@brett20000000009 Yeah, I find of figured as much. Backlight modifications/poking of this nature is something I have considered before but avoided for the reasons you pointed out, and because I am electrically incompetent :)

[@oneMurilognt]

Nice

[@NotThat3]

Is there a way to remove vblank from the signal? Is it necessary for PC monitors? Also personally I keep Dyac+ enabled 24/7, gaming or browsing on 240 hz. I understand 60 hz is much harsher on the eyes. Can't a 240 hz (or 120 hz) monitor be used as a 60 hz replacement by drawing each frame a multiple of time, including multiple strobings? I never understood why a 240 hz monitor needed to slow itself down to 60 hz to fit 60 fps gaming. If we rewrote monitors (and the signal coming from the cable) from scratch, could a better solution not be found?

[@yoked391]

ViewSonic XG2431 60hz backlight strobing👀

[@Weaver_Games]

I gotta say the 60 and 120HZ strobing on my LG CX is absolutely amazing. On the highest setting at 60 there is visible flicker and it's darker, but the motion clarity is absolutely the best I've seen since the CRT days since OLED pixels are stupid fast.

[@MKR3238]

I tried to use it in pc mode but the setting is locked :/

[@ApertureGrille]

LG is really doing wonders with their CX. I haven't seen one in person, but from everything I hear, they're super close to making "gaming" monitors useless.

[@MKR3238]

@@ApertureGrille they definitely show how overpriced high end "gaming" LCDs and those nvidia BFGDs are

[@brett20000000009]

​@@ApertureGrille they only get to 4ms persistence with a 75% brightness loss. which is still not quite super clear motion especially for 4k. I think 1ms is about what you need for perfect clarity at 1080p

[@Weaver_Games]

@@ApertureGrille If I was a millionaire I'd buy you one to test haha. Unfortunately I'm a nerd of conventional means :p.

[@ThisRandomUsername]

It would be interesting to know where in the system the undershoot is introduced. Theoretically it could be in the driver itself, not the panel circuit. If you get back around to it, perhaps trying a 'cheap' driver board from Aliexpress would be interesting.

[@doltBmB]

It seems to me that the first priority should be to replace the LED's outright with something much brighter, instead of pointlessly trying to overdrive LED's made for continous operation, get some dedicated strobing LED's that can go really bright for those short bursts.

[@eriseldplaku]

Can you do that on a Ccfl backlight. I think my montior flickers at 180hz and if the ufo test I can see like 3 images of the ufo. Not a ghost but like 3 ufo stuck together. I wonder if 60hz would help with motion cause at 180hz there is still a lot of blur, but not as much as without no flicker at all at 100% brightness.

[@brett20000000009]

Maybe try cutting diffusors and also adding in another ledstrip on the other side of the monitor for double the brightness. Also voltage boosted strobing is a thing dyac does this I think.

[@ApertureGrille]

The LED strip I showed in the video came from another monitor where I, uhh, accidentally destroyed the backlight diffusor when trying to cut it. I'll be more careful next time :) I like the suggestion about adding another LED strip. Hah! More is better! I was also wondering if I could add in narrower bandwidth RGB LEDs to increase the color gamut of the monitor.

[@anothergol]

I find it fascinating that everyone is obsessed by ELMB at 60Hz, instead of 70Hz. I get it that today if a game is designed for & ticks at a fixed rate, it'll be 60Hz, but let's not forget that the good old mode 13H was 320x200 at 70Hz. Pretty much all games in VGA mode were running very smoothly at 70Hz (with ocasional ones in 320x240 at 60). 70Hz makes a big difference, it eliminates the slight flicker still annoying at 60. On my CRT I play at 75 or 85Hz, and it's pretty much perfect, for a rather little amount of extra GPU work. But yeah, that most monitors only allow ELMB starting at 120Hz, I just don't get it.

[@Internetzspacezshipz]

Hey looking back at this video after your recent ones, I wonder if you couldn't just add more backlight LEDs and strobe them at the same time as the other ones? I don't know all the details though, so maybe that's impossible.

[@jimbotron70]

What about the BFI (black frame insertion) trick?

[@rockrl98]

open source monitor hardware/drivers would be f-ing great

[@displaytalk]

Doesn't the samsung odyssey G7 do 60hz strobe? It says it does in the rtings review..

[@diamony123]

Im looking forward to doin the same, i ran into your video for encouragement. Too bad you couldn't have done a slow motion video.

[@ApertureGrille]

Might not be necessary since the BlurBusters certified ViewSonic XG2431 should be coming out soon!

[@diamony123]

@@ApertureGrille I'm doing it for experiment. My goal is to make an lcd play movies like a film projector. My plan is to use some blank space at the bottom after each frame. This should give some time to allow strobe and prevent crosstalk.

[@perdana5786]

Maybe a software driver based overdrive can fix the slow transitions?

[@fernandoanatomia]

Wowwww

[@aeliussaionji6225]

Awesome video! I do want to point out that the samsung CHG70 does strobe at 60Hz, without any modifications. Actually, it strobes at literally any Hz. It'll strobe at 24Hz! That is truly unbearable to look at though :) You just enable strobing, and whatever Hz you switch to, the strobing adjusts accordingly. The VG248 is also capable of 60Hz strobing, but that's not a stock feature. It's one of those old lightboost monitors, and ToastyX developed a tool to make it strobe at whatever you want. I just replaced my CHG70 with the Odyssey G7 and to my horror, the G7 only strobes at 240Hz, and even at 240fps/240Hz, it really doesn't even work. Incredibly disappointing on that front. However, the G7 is stronger in most other ways and I still have my CRT, so I'll let it slide... I absolutely do not trust myself to modify my G7, but it'd be nice to add a second backlight to it specifically for externally controlled 60Hz strobe. If I turn the brightness down enough on the monitor and turn on the strobing light... maybe that'd work ok? 😅

[@aeliussaionji6225]

I hope this isn't rude or tonedeaf of me: but I'm looking to sell my CHG70. If you're at all interested in covering that, I'd happily sell it to you for $100 below the current going rate on ebay.

[@ApertureGrille]

@@aeliussaionji6225 Let me get back to you on that!

[@displaytalk]

Damn, the rtings review for the G7 says it does strobe at 60hz. Where does the confusion come from? Also, their review for the CHG70 contradicts what you say. They say it strobes only as low as 100hz

[@aeliussaionji6225]

​@@displaytalk rtings just notes the frequency at which BFI is able to be enabled from the OSD. Remember, the strobing frequency can be distinctly different from the monitor's refresh frequency. It's strobing at 60Hz, but the strobing is not 60Hz :P G7 seems to have exactly one BFI strobing frequency: always running at what might be 240Hz, even if you use the OSD to change the refresh rate to 60Hz. It's therefore quite useless as a BFI. I complained to rtings about their high bfi score here, because I naively assumed "rtings gave it a good score, must be good". Turns out they actually don't have a comprehensive metric for rating BFI, and they merely note if BFI can be enabled at highest and lowest Hz and call it a day. They told me they're working on improving this. I told them "60Hz bfi strobe is very important please take note". As for CHG70, they're incorrect but it's probably not their fault. The OSD is actually a bit buggy. It's probably accurate that Samsung don't intend for you to enable BFI below 100Hz. However, to my eyes (I don't have measuring equipment) the firmware changes the BFI strobe to match the refresh rate. If you enable BFI and then use Windows to change to 24Hz, the firmware will strobe at what looks like 24Hz to me. I'd be willing to bet the OSD doesn't let you enable BFI and then select 60Hz, but it still works if you use Windows to change the Hz. That clear things up?

[@displaytalk]

@@aeliussaionji6225 jesus christ that's awful. Thanks for the explanation

[@perdana5786]

What would be a better gaming experience? Question 1: A perfect strobed monitor at 60hz (As in 1ms flashes or less with no crosstalk and image doubling artifacts with ample brightness) playing at a locked 60fps or a non-strobed high refresh rate monitor playing between around 120 - 144fps with freesync. Question 2: A perfect strobed monitor at 120hz (As in 1ms flashes or less with no crosstalk and image doubling artifacts with ample brightness) playing at a locked 120fps or a non-strobed high refresh rate monitor playing between around 180 - 240fps with freesync. Question 3: Why aren't any manufacturers coming up with a category of monitors that don't feature super high refresh rates but instead are focused primarily on strobing perfectly at lower refresh rates like 60hz or 120hz. This would make gaming at lower fps much more smoother and reduces the need for powerful graphics cards or cpus to get a super smooth experience. This also allows us to push the detail settings and resolutions higher without sacrificing motion quality. I really wanna know what you think @a5hun, since it seems you're the most qualified to answer these questions. I would really appreciate your insight. Any input is welcome.

[@ApertureGrille]

For your first two questions, it depends on the type of game. For racing games, I'd always go for the strobed display, but let's consider a broader selection of games. For Q1, I'd go with the non-strobed 144 Hz monitor. For anything with mouse camera control, higher framerates always feel better. I don't want to play Quake Live at 60 FPS! For Q2, I'd switch my answer to the strobed display. 120 FPS is enough to finally feel smooth and responsive, and coupled with the clarity from the strobes, I'd definitely take that over the VRR display. For Q3, I actually like the push for higher and higher framerates for monitors, as long as the prices stay reasonable. Higher top end frequencies allow better adaptive-sync overdrive behavior over their full range through LFC. And the faster and faster panel scan-out also helps with strobing modes. I can see a point in the next few years where LCDs are hitting 480 Hz, and if the pixel response times keep improving, those displays would be able to strobe, not just at 60 Hz, but at 120 Hz super cleanly.

[@prismflux5129]

Would you say that the picture is better than before? Except for brightness

[@nayeemhossain875]

Hey does this monitor has power button?

[@Dr.Kryptanical]

fire retardant carpets on the wall as sound proofing... why didn't I think of that!

[@Aomicplane]

Very interesting video, really liked it! But aren't the ZOWIE XL2546, XL2546S and XL2546K able to strobe at 60Hz? I own the XL2546S and as far as i'm aware that is possible

[@ApertureGrille]

Ooh, I didn't know that! That kind of makes my complaints pointless.

[@brett20000000009]

​@@ApertureGrille I would check that first most zowies i know do not support single strobe 60hz including my 2540

[@ApertureGrille]

www.bijanjamshidi.com/benq-zowie-xl2546s-1 Here's another good reviewer's site. On his pursuit shots, it looks like the XL2546S double strobes at 60 Hz. Is that what yours looks like?

[@Aomicplane]

@@ApertureGrille Looks kind of similar but not 100%. Took some sample pictures myself at 60Hz (as best as i could), posted them here: postimg.cc/gallery/1Zjdq8v. Honestly i don't know what the difference is between single and double strobing, i'm not really the most knowledgable person on the subject matter. BTW i also watch Bijan, you two are the go-to channels for in depth monitor reviews! :) On the pictures i had the monitor at 60Hz, DyAc+ on premium and AMA on high, the test was running at 960pixels/second (should have ran it at 1200pixels/second)

[@brett20000000009]

@@ApertureGrille mine completely disables strobing for anything under 100hz. I have a 144hz benq that will double strobe at 60hz but you can use the service menu to enable single strobe. unfortunately all the single strobe capable monitors I have tried do not have high enough VT's to hide all the crosstalk you can get about 75% of the screen clear. check out my thread on blurbusters forum I have some badly taken pursuit shots and video search "World first zowie XL2540 240hz 60hz singlestrobe? Experiment."

[@plutoisfrosty]

try xl2546k with 60hz backlight strobing/Dyac

[@ApertureGrille]

Unfortunately, the XL2546K double strobes at 60 Hz. The best bet we have for proper 60 Hz strobing is the ViewSonic XG2431, which'll have the BlurBusters 2.0 cert.

[@chengbaal]

bro. what are you doing to your speakers setting them against the wall though.

[@ApertureGrille]

Finally! Someone noticed the speakers! :) The two main speakers aren't ported, if that's what you're worried about. I pulled those drivers from a pair of Polk RT5s and put them in a very hastily put together sealed enclosure. But the crossover is fully electronic, controlled by the PC, using brickwall filters and phase correction. I've high-passed the tweeters at 1.8 kHz, and the mid-woofers at 150 Hz. Everything lower is sent to the 12" woofers at the sides. It sounds really good, and I've used REW to make sure the frequency response is as flat as I can get it down to 20 Hz. DIY speaker building is one of my other hobbies! If you want to talk speakers, I'm up for it!

[@chengbaal]

@@ApertureGrille good man. unfortunately, i haven't had the pleasure to build my own. I've only got some micca's on my tiny desk.

[@rtyzxc]

Hi, can you investigate what Zowie's DyAc backlight strobing does? On their site, ZOWIE claims that their DyAc backlight strobing does not cause increased input lag, which I find hard to believe. ZOWIE_Support on Reddit vaguely says "i can't disclose design details due to confidential information, but what a DyAc design maybe not exactly as same as your presumption."

[@Isaac________]

What is the CAD value / metric? I can't find anything on Google with different keyword combinations I've tried

[@ApertureGrille]

CAD stands for cumulative absolute deviation. I cover it here: kzbin.info/www/bejne/rnWlaqaFg8t9a7M CAD takes the absolute value of the difference of where the LCD response is vs. where it ideally should be. If you add all those values up along the response, you get a kind of "area" measurement that gives a great, one-measurement assessment of a GtG transition's quality. Hardware Unboxed uses something similar for their reviews, but they call it Cumulative Deviation, which is a little easier to say. :) Instead of response time numbers and overshoot percentages, I think that CAD is a much better way to characterize a monitor's performance.

[@Isaac________]

@@ApertureGrille thanks, makes perfect sense!

[@Isaac________]

@@ApertureGrille if I understand correctly, you stretch the curve additionally to punish overshoot. Is that just a linear factor or something more severe?

[@ApertureGrille]

@@Isaac________ I use a linear ratio for the penalty, 20% CAD multiplier per 12 RGB overshoot (so 10% for 6 RGB overshoot, etc.). I spent a lot of time trying to find the "perfect" penalty to apply, but it is still subjective. After looking at the average CAD score on a bunch of monitors with a many different overdrive settings while looking at my Frog Pursuit program and playing games, I think the 20% penalty provided to closest match to what we see. The pure "area" measurement without any overshoot penalty wasn't catching just how visually distracting high overshoot was, even if very brief. You could make a case for using the difference from ideal squared, like in the calculation for variance, but I would need a focus group of monitor enthusiasts to help me dial in the ideal penalty. CAD really should be called PANCAD: Perceptually Adjusted Normalized Cumulative Absolute Deviation. :)

[@Isaac________]

@@ApertureGrille It sounds like you're halfway to a paper publication at this point! ;)

[@EggBastion]

CAD?

[@sundaranandadas]

1:45 can somebody tell me that keyboard name?

[@DarkLOLable]

If you look closely you can read "Phantom". You can probably find it searching for "Phantom keyboard".

[@sundaranandadas]

@@DarkLOLable thanks! I was on the phone, couldn't see it

[@shanksisnoteventhatstrongbruh]

Tecware Phantom 87

[@brane2379]

Why fuck around with PWM ? Just power the backlight leds with settable DC current.

[@AndreyLaran]

давай тепреь повтори но не лазия в моник а прсото прикурти ардуину к активным 3д стерео очкам и покажи картинку через них