DIY Dual-Layer LCD monitor - can it match OLED??

Dual-layer LCD monitors aren't hard to make, but can they perform? AD: Want to try Huel? Visit: rebrand.ly/mat... it’s SUPER tasty! Thanks to @HuelYT for the sponsorship!
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[@DIYPerks]

🥦 Let's hear it for the random broccoli

[@Quinitix]

Lets gooo

[@hiroshi7025]

Hello I'm the broccoli and I wanted to say that this is really cool. Thanks, Matt.

[@owensparks5013]

Or we could burn it with fire, encase it in lead and then eject it into space. Options.

[@arfan521]

Does that count as one of 5 veg's for the day?

[@SuperDiamondace]

Next try the laser tv

[@bijeshshrestha2450]

ah yes, built in anti aliasing

[@phoenixyt124]

And extra ghosting. For free!

[@Josuh]

sprite artists and emulator mfs are in shambles rn

[@burger1113]

"physical," too lol

[@lost4468yt]

You already get built in AA with higher resolution.

[@jocelyndeguise]

If you fed both screens different HDMI signals, like in a "mirrored" dual monitor computer setup (using two outputs from your graphic card), you'd be able to adjust both layers individually. This could help making the picture's colours less "poppy" and maybe even help increase the white levels.

[@Tattlebot]

Not in this case, as while you're squaring the contrast ratio, you're also squaring the total light blocking, which is already about 97% on LCD.

[@fuzzywzhe]

I don't know, but they might have slightly different vertical blanking intervals - meaning one monitor might start refreshing at a slightly different time than the other. I don't KNOW this to be true, but I suspect it might be true. That might be causing some problems, but really, I know about the technology of the LCD itself, but not the details of how it works.

[@Dl2X-qo6by]

Does it then akt like a holo display (possebly if you increse the distance between them by a bit) but id like to see a DIY holo-skreen

[@nikita_kostin]

or be able to watch 2 full screen KZbin videos simultaneously)))

[@pr0xZen]

​@@fuzzywzheif running these from identical type outputs from the same quadro / Ax000 card or Radeon card (AMD is significantly less tight about locking up feature access on consumer GPUs, but low tier quadro cards are more bountiful harvested from old workstations), there's a ton of possibilities for adjusting stuff here to compensate for sync issues, gamma curves etc. Metrics and results should be pretty reliable, especially if you can get both displays sourced from the same production batch (almost guaranteed if bought new together). As that should avoid any internal revisions that wouldn't have noticeable impact on 2 individual monitors but could cause headaches combining 2 independent panels into a single display sandwich.

[@drk_blood]

It is literally kind of a dimmer OLED but without any risk of burn-in 🔥 Really well made ! Great job man, your creations are incredible.

[@ppsarrakis]

also this uses like 300++watts thats 4-5 times my 34inch+24 inch monitor combo

[@drk_blood]

@@ppsarrakis power is cheap in my country. It's ok, I would rather buy a good oled than this but it was interesting for me to see such thing can exist and actually work.

[@IncognitoActivado]

@@ppsarrakis I don't care.

[@axux4509]

I would just buy a mini-led monitor

[@ttsuter87]

This guy is great…every time I have that question lingering in my mind as he’s showing it, he immediately give the explanation or reason for how something works for his projects. Like he reads our thoughts. Great informative video. Wish I had the resources and time to make one myself. I’d want to try this on some older cheap lcd tvs

[@54V4]

As a multimedia computing graduate, this project is simply priceless. Not just the project itself, but rather also understanding of the inner workings of a monitor. Throughout my four years of uni’ I’ve not once been explained that the LCD is taking advantage of polarisation to produce the images, as you’ve explained in very simple terms. I could not thank you enough.

[@hxhdfjifzirstc894]

Education these days is basically worthless -- only the most shallow details are covered, and the average person will learn far more if they simply do their own research.

[@earthtaurus5515]

@@hxhdfjifzirstc894 Nope 🤦‍♂. It's that Education often is severely underfunded and understaffed. Not to mention, if results are not "produced" funding gets cut so the material for general degrees is simplified to ensure a higher pass rate. Unless you choose very specialised subjects - that knowledge is actually needed as a foundational layer.

[@DougDingus]

I find your comment about not being taught how an LCD display actually works as amazing as it is concerning. I am amazed there are people who can some how rationalize that gaffe. Of course my concern is obvious with my only real wonder being, "what the hell else is missing??"

[@disadadi8958]

@@hxhdfjifzirstc894 A pretty wild exaggeration.

[@disadadi8958]

@@DougDingus Sadly university is more about learning yourself than being taught everything. I'm certain that appropriate courses that cover display technologies can be found, as there are more complex things taught there as well. However, they mostly rely on people actively studying stuff on their own, and the main point is on how to find and process new information from various sources such as books, journals, and other publications both in paper and online. OF course, it's not perfect either. That's not what I'm saying. I was thoroughly disappointed with uni education at first during my undergrad studies, but I've found things here and there that are worth mentioning and appreciating for.

[@fatchulanjaza2433]

Unlike any other channels, this channel project literally take time, effort and innovation. But that makes it even more special. We're always waiting for the next video to release. Great job as always.

[@andrewlalis]

This isn't the only channel on this website whose projects take time, effort, and innovation

[@Granhier]

If only you'd put a similar time, effort and innovation into your comments instead of generic "praising others at the cost of putting everyone else down" statements

[@fatchulanjaza2433]

Guys I'm not trying to say its the only channel, or putting everyone else down. Thanks for reminding me. I'm not an english native speaker and I'm still learning english. 🙏

[@Ganesh_Sh]

While I usually find his DIYs trying the best & practical solution, this one has scope for a lot of improvement. 1. The large backlight led array: This is what makes this build thick, impractical and causes high power consumption. This can be avoided if tracing paper is not used. A better solution for the polarization problem is the way forward, which leads to #2 2. Tracing sheet: 2 stages of tracing sheet was used - one between the panels and other in front of the backlight. Both can be avoided. Fix / Recommendations: The polarizing element in the lcd panel is actually removable. He has to further separate layers of the lcd panel and remove the polarizing layer from the base panel. This removes the need for tracing paper and a more powerful backlight and solves blurry text issue. Second step is to change display settings in outer panel to high contrast black and white while inside panel displays full colour. This will solve the color gamma issue and the outer panel will only enhance blacks.

[@DoxSteele]

We have panels like this on a lot of our casino floors! IGT made a unit called the G23MLD (Multi-Layer Display) that has 2 LCDs stuck together to achieve a 3D effect on the slot theme. Most of the time the reels are on the back monitor and the line indicators are the front monitor

[@brandonf2562]

As soon as I saw this video I thought the exact same thing. We have them as well but most of ours have developed black spots. So I question the longevity of the monitor, but that one still looks much better then the IGT version ever did.

[@DoxSteele]

@@brandonf2562 Have you been making sure the fans are working? One of our older tech was saying that half the screen wouldn't be working soon after the fans died

[@jek__]

Pretty neat, and very clever! The thickness bothers me 0%, it's still far lighter and thinner than many computers I've used in my life. But the increase in energy cost over time and the slight fuzziness are issues that i think would steer me away from making one

[@mechanizedMytha]

i wouldn't be surprised monitors are often lighter than computers if we're talking about desktops, but this isn't an AIO if that was the persuasion you caught

[@snintendog]

I mean the thickness could be fixed with a good diffuser that isn't baking paper would help the power consumption as well given the LEDs dont need to be as bright as before.

[@shApYT]

Have you tried to remove the polarization layer on the first screen, like a lot of projects do to make "secret" screens that only show up when wearing polarizing glasses?

[@JoakimPekkari]

I had the exact same thought!

[@Elemental-IT]

when you remove the polarizer, the lcd becomes plain white - negating the effect.

[@PixelBrushArt]

@@Elemental-IT Well, one of the displays still has it's polarizer.

[@3ATIVE]

@@Elemental-IT You'd have to remove the polarizer of the back layer from the top panel and the front polarizer from the bottom one.

[@greenaum]

@@Elemental-IT That's the point of the polarising glasses. You take the front polariser off the LCD, so the LCD is plain white and unreadable, yes. Unless you're wearing a pair of polarisers in front of your eyes. It's a silly hack but I suppose fun, I wouldn't do it to a monitor I actually wanted to use.

[@jamescampbell8482]

@DiyPerks Some people have mentioned rotating one of the displays so you can use one polarizer to increase brightness. You could use a custom VR type application where you could keep the two panels synchronized but have one image oriented one way, and the other another way. Instead of a left eye and right eye, the stereo image would render to the two seperate panels but be in sync with their own orientation that you would program into the Distortion shooter.. Make one of the layers monochrome, and that will also increase brightness

[@JamesJansson]

That is pretty cool. I feel like this would be extra nice for text in 4k. I want to go to OLED for my monitor but worried about burn-in. Dual LCD might work, if it was actually available for consumers.

[@jeroenvdw]

I shouldn't worry about burn in, there are safety measures with any new oled monitor like pixel shifting which you won't even notice.

[@bradensinclair9517]

If you look after your display burn In isn't a problem

[@jeroenvdw]

@Joao_M hmm yeah makes sense if you use it for office programs. The pixels shift but 99% will shift to the same color

[@peceed]

*EUREKA* ! You should flip one them. Back to Back or Front to Front. This will keep orientation of adjacent polarizers aligned = no light loss, problem solved. No diffuser and stronger backlight required. Then rotate flipped one 180 degrees, to keep RGB pattern aligned. Then all you need is to change orientation of displayed image on rotated and flipped display - just mirror image up-down. The only drawback is the opposite direction of the image updates, which can lead to minimal artifacts in the dynamic scenes far from the center of the image. In your current DYI solution it is better to use polarization filter foil angled 45 degree between displays, it improves light loss to 50% (diffraction gives 25% in the best case, 50% is lost on wrong polarization, and 50% of the left on wrong direction). More filters can rotate the polarization with less losses.

[@burger1113]

Crazy project! No other channel consistently blows my expectations away with every video lol

[@abigguitar]

Some LCD TVs use a variable brightness array of LED backlights. When the image requests black, the individual backlights behind the "black" areas dim to almost nil, making these areas of the screen nearly black. When white is requested, obviously the backlight array in those areas will be at full brightness. For greys, the backlight can choose various levels of brightness. These array dimming LCD backlight technologies are probably the smartest I've seen and can compete with "expensive" display technologies like OLED in contrast ratio, but are overall much, much cheaper to build and buy (less than $800 or cheaper). I've owned two of these TVs, one a 1080p TV and one a 4K TV and both work exceedingly well for gaming purposes and movies alike. You can also switch this technology off if you like, but I don't know why you'd want to. Not all LCD TVs offer variable brightness backlight technologies, so you have to look for this feature specifically. I should also point out that the only time this variable backlight technology doesn't really work fully is when the vast majority of the screen is light with only tiny amounts of black here and there. The LED dimming backlights aren't sufficiently granular enough to support high contrast when it's down to just a few pixels of black. For that, you really need OLED.

[@malcolmrains2426]

Please make DIY e -ink monitor!!!

[@dragonhart6505]

i switched my HP 27M monitor image settings from Limited to Full Range in the OSD, then overclocked it to 76hz with CRU (which for some reason made blacks darker as opposed to 60hz...no changes in Nvidia Control Panel, fyi.) Blacks are black, it's bright af and looks beautiful next to our 65" HDR tv in comparison. i'll stick with that, but this was a fun video to watch

[@monitorsunboxed]

Do you want to send it over for testing?

[@ĘŁĞPS8]

Yeah

[@Rocky.G]

videos like this are the reason i m subbed to you since 3 years now !! Keep it up brother !!

[@perdana5786]

This project needs to be revisited and revised with suggestions from the comments such as a different type of diffusers, correcting gamma, creating icc profile for color calibration. Just to see how far we can push it.

[@StupidusMaximusTheFirst]

That's a brilliant idea. If dual panel monitors already exist though, manufacturers have already thought of this. And they could overcome and solve all the problems you faced in your build. I think they do not want to promote dual panel displays as much as OLED, cause although it's cheaper to build a dual panel monitor yourself than get an OLED one, OLED tech might be overpriced. For manufacturers, OLED is most likely much cheaper to make than dual panel monitors, despite what they are asking for it.

[@Vermilicious]

Assuming the signals to the display are digital, you don't actually need to double the other innards of the monitor, just double/split the signals.

[@jiegao3591]

I think some panels can just have their polarization layers peeled off, and although I'm not sure if this damages the panel or not, it might be interesting if this was revisited with one of those.

[@ameenkagzigaming-gmailcom]

Just like the action lab

[@angelic_aether]

absolutely love your videos and the way you explain things, good job!

[@Kholdstare0503]

Pardon my French mate, that.. is fucking impressive! You really have a genius mind! That looks amazing!

[@marcusbouge4848]

Great to see Theon Greyjoy building a LCD monitor

[@Divyam_Deep]

I love it when people do these things This is a great DIY but from what I've noticed, the sharpness of the images being displayed would drop down significantly as the light is scattering a lot but overall great work!

[@BronxXxBassTV]

looks awesome ! i would love to watch a movie on this

[@templar.]

not sure if you read your comments but i loved your brass pc and microphone builds. i would looove if youd make a guide on how to build your own high quality (4k) webcam

[@g6autobot]

Another great project thanks for the videos. it would have looked fantastic in brass.

[@squareeyes1117]

This is really interesting. Anyone with a samsung phone knows how incredibly rich and deep the image is, OLED/AMOLED. However as you mentioned, they're very expensive and just simple are not as fast as other panels like TN or IPS. However, I find that the best middle ground for colour, contrast and affordability is 100% VA. The blacks are infact very deep for an LCD

[@kaan.0]

oled panels are faster than TN, IPS and VA panels

[@TraderOnYoutube]

i love how his videos are recorded like they are improviser, but therr goes days of plannig

[@ivanmarkovic8885]

Some image processing so that LCD don't show same image, but two different that will combine into one presumably much better...

[@adamsamson2699]

Really interesting looking back at this now that tandem oleds are a thing

[@nonaurbizniz7440]

If you want a high refresh lcd monitor for pc gaming that rivals oled perfomance and such that doesn't break the bank the hisense u8h is currently priced at $650 for the 55" and its as close as you can get to oled performance and not be oled. This project was hella cool though.

[@emizaquel8779]

I feel like a riskier construction for this would be to remove the polarization on rear LCD. It's possible, if risky, to do so and may reduce the light lost overall allowing for lower power consumption and brighter displays.

[@andchip.s]

Maybe a modernized CRT? Nice Project DIY Perks !!

[@Jcewazhere]

Get one of those fiber optic suncatcher sunroof thingies and pipe it into the panel. Hybrid solar powered backlight

[@wtchr_]

Thank God my monitor is able to display level of black you achieved with this build. 😁

[@duckilythelovely3040]

Qled monitor is what I'd like. I don't care about slight blooming. Not often my screen is black entire, with a white letter O in the middle.

[@TETRINO]

A few years ago a company worked on releasing consumer verions of this as a cheaper alternative to full array dimming/OLED panels. They used a greyscale panel at 1/4 resolution (basically 1080p for the 4K displays they were working on) panel for their backing panel and it worked very well. They only took one screen to market unfortunately and it never reached the EU or US. By the time it reached market, the price of FALD and OLED displays were competitive even at the low end, and it wasn't worth working out the engineering overhead to bring prices down. A shame, as a system it can work as you see yourself!

[@kylestevenson9699]

10:52 You forgot to mention one thing(or at least I missed it if you did), a project like this is very dangerous. If anyone tries this, they MUST learn how to drain the change from the monitor or they may kill themselves when the backlight and other high voltage monitor parts shock them.

[@fadimufarrij661]

I am not sure about what I am going to say because I don't have money to try my idea. but what about removing the black polarized film from one screen and the keep other one with the polarized film. this will help the lower screen to be white enough to let the light go throw. the second idea is to put an Amoled black polarized film on one screen only and double the backlight. this will make it nearly amoled. I don't know if that will work but I would love seeing you trying that out.

[@TheJRSvideos]

You’ve essentially made a DIY Apple XDR Display, which basically works the same way. 😄

[@HadouGun]

I think potentially you can make close to the perfect screen if you got a PG27AQN and gave it dual layers stuck the first layer to a Glass panel, figured out the right polarisation method, then increased the brightness so that it could reach 1500 Nits peak brightness. Not sure how the ULMB2 would work for that since I'm sure they calibrated ULMB2 for the brightness values it had in testing. Since the technology requires space in-between elements you could probably make the backlight modular so you can hot swap it later on. But what this gives you is a Glossy 360hz 1440p Panel with High contrast ratio and OLED Quality Blacks with enough brightness to have the best HDR on a PC monitor available.

[@shyataroo]

What about adding a quantum dot layer and using Mini-LEDs (side effect is also more contrast zones!)

[@jdavis.]

To calibrate these, you could get a Spyder X device to make sure the colours are totally accurate

[@hi-tech-guy-1823]

There is is a Tracing paper that actually plastic milk White acetate sheets - Craft Plastic Sheets A0 ~ A5 sizes it has better light Pass though There used for some moving Projector Arts projects and building Layouts / PCB's / Stencil Sheets even White Cellophane Gels

[@AaronJNKS]

PLEASE! Try to calibrate it with with I1display pro or any else monitor calibrator. Would be great to see a proper tones

[@MattFriend]

Thanks for making me notice all the flaws in my expensive gaming monitor! 🤣

[@accelerator5524]

While seeing the amazing black levels through my LCD screen: wow it is so dark compared to a normal LCD xD

[@germimonte]

if you rotate the second panel 90 degrees you don't need the tracing paper, just a bigger panel and insanely complicated logic for alignment

[@SrgntPickles]

The irony of trying to see your display quality on my normal monitor has not escaped me.

[@me_is_here760]

just make the grid of lights behind the screen light up brighter where the screen needs to be whiter and light up less where is should be dark on the screen

[@queasycarboy508]

I'm curious to see how perfect the blacks of a triple layered LCD! If anyone tries to build a triple layered LCD, can anyone tell me whats their experience?

[@1marcelfilms]

Great you simulated the blurryness of a crt

[@JohnWick-dg2rl]

You told about another Submarine video. We would like to see that as well.

[@VarietyGamerChannel]

I have an Auros OLED 48 inch PC monitor. Some annoying quirks but it goes far beyond anything else visually speaking. Most annoying is being forced to turn it off every 40 or so operating hours for the screen to de-ghost and prevent burn in. This takes a few minutes though.

[@mikebenstead7600]

I'm a Karaoke host and I'm looking for a different kind of dual monitor, one that displays front and back. so the singer and the audience can both see the words on the screen. They do exist but the cost is prohibitive. I could simply buy two screens but I'd like to reduce the weight I have to carry to and from gigs. I think that simply reversing your second LCD panel should do the trick but I'd be interested to see if you can foresee any issues with that plan?

[@nsalazar]

3:40 dead pixel 😞

[@jeremyfisher8512]

For 1080p monitors or if you get a good deal on some 2k monitors this seems great

[@alexiscorrigan6487]

Would have been a better experience watching this video if my screen was double LCD!

[@orpheuscreativeco9236]

Energy costs + extra bits = ...$1K - $3k ✌️😁 Very cool experiment though! Thanks for sharing your knowledge with us 🙌

[@Mr.TomMoon]

Hi Matt, i have your "perhaps" next diy project or experiment. Can you make an laser cutter? Cause they are very expensive and yes only a cutter is enough :D

[@leomysky]

Wonderful experience, thank you for the video

[@flint7777]

this man is a legend

[@Waynesification]

Sharp did design panels with 90% light pass through. You probably will find others with 75% these days. I don't know how many are 50% or less these days.

[@anlitbinish7195]

@diyperks if you remove the polarizer and chande its angle.should make it brighter

[@drfrancintosh]

Time traveling from Jan. 2024 - could you remove the polarizing layer from one of the LCD panels (the lower one)? I've seen this done (and done it myself) by laying wet paper towels on the panel for a couple hours. Then the polarizing layer pulls off. It makes for a sort of "secret" LCD screen, because the LCD is not polarized - but if you wear polarized sunglasses it is visible again. So - you could remove the polarizing layer from the lower panel, leave it on the front panel, and you don't need the "defusing" layer of paper.

[@Nekudon]

VA panels exist! I'm using one right now.

[@AhrennerhA]

I want to do this but not improve the contrast or image quality although thats a plus, i want an extremely dark night time monitor, something basically no manufacturer seems to make. I have two monitors and ive already opened up one of them just gota get a hdmi splitter 😅

[@xenon2Merchant]

I wonder if "doubling" colors is the right choice, maybe one of the panels should be turned into BW mode. Cool video!

[@FelanLP]

Wouldn't it be possible to connect two panels (just the panel) onto one single controler? I mean the panel doesn't send out any information. Means you just need a splitter to send one signal from the controler to the two panels. Similar to connecting two headphones to one port. Then you just need to remove the polarisation layer fom the second panel. This also eliminated the need of a depolarisation layer since you only polarise the light after it got through both panels.

[@guyfromostrava]

Your content is just great!

[@fiaca22]

como me gustaría tener estos videos en español para verlos con mi familia en la cena jaja

[@flavoredmoney29]

I was wondering that if it is possible to use this technique while using 2 different resolution LCD panel, the lower resolution will be in the back, while the higher resolution in the front. I think it could work but only if the back LCD is half the resolution of the front one, but it would be harder to get a 960 x 540 for a 1920 x 1080 then just buying to 1920 x 1080.

[@sklynexd]

No it can't, OLED is a category on its own, it's a pure superb display tech with almost zero drawbacks just the burn in. The best colors, the best blacks, each pixel is a dimming zone, superb HDR performance and Dolby Vision support. And probably any OLED is still better than any LCD. And brightness isn't really an issue, I have 600 nits on my LG B3 and it's not even at full brightness.

[@sanguine.dreams]

If you added a 3rd panel it would allow light though ;)

[@kettch42]

I think you need the 2nd layer to be monochrome and close enough to the first layer that there is little spill between pixels. Then the 2nd layer should be opposite polarity of the first. I'm wondering if most of the gains you accomplished were just because the entire scene is dimmer.

[@parawizard]

Cool experiment! I run mostly OLEDs and it always surprises me how much image blurring there is on LCD panels in comparison.

[@Ag89q43G0HyA]

this is probabably the solution, we just need new 12 bit LCD paneles, so we can adjust the brigtness in HDR content more. I say this cuz my new xiaomi 12 has a 12 bit display and it can show hdr content in lower brightness levels, my galaxy s10 cant show hdr with out setting the brightness to max due to the 10bit panel. I hope manufacturers began to do this.

[@naciomay8582]

Thats amazing..I was wondering is it going to be posdible to create a glassless 3d viewing by using multiple monitors? Weird idea maybe 😂

[@meonlime4010]

This monitor looking like a project m waiting to see from you DIY iMac

[@waynetuttle6872]

I wonder how well this would work on a high quality IPS monitor, something nicer than a "free with your purchase of a HP" monitor

[@rayman5704]

It's just incredible! 😲

[@louiec.9782]

Still can't believe the dude from game of thrones built a TV. Mind blown.

[@AMOne77V12]

If I remember correctly, Hisense has done this in one of their TVs. They achieved incredible contrast levels by using a second monochrome LCD layer to provide those inky blacks. Sadly, I don't think they've pursued it any further, synchronizing the LCD layers was quite difficult.

[@zachb1706]

Apple -did it- didn't do it Edit: sorry, the Pro Display XDR is not Dual LCD. I swear I heard it was when it came out, but that was a myth

[@anishhegde5197]

LTT has made a video on it

[@anishhegde5197]

@@zachb1706 nope

[@ugur3527]

@@zachb1706 did it on where?

[@MrRagsd]

I have one of these Hisense TVs it’s amazing except one of my back panel pixels died. Twice as many to go wrong I guess.

[@samtorbert6554]

I'm just amazed how accurately you were able to align the two LCDs

[@UhOhUmm]

Pixels on a 1080p monitor are not actually all that small, you can see them with your eyes if you get close, so it's not as hard as you might think.

[@kunjupulla]

Why does this video only have 700 likes? Edit: my KZbin glitched

[@siggie8610]

just use some sort of end stop lmao

[@user-a6olopvmv9]

Valid question. Misalignment can lead to Moire easily.

[@ViciousVinnyD]

@@user-a6olopvmv9 Moire shouldn't be an issue if the tracing paper blurs the image enough to eliminate pixel boundaries. Effectively turning the back screen into a local dimming layer while the front screen creates a sharp image.

[@EnvAdam]

I would love to see a V2 version of this where you dissemble the panels further and experiment with various filter layers.

[@MelroyvandenBerg]

I AGREE! 2nd version soon!?

[@unperrier5998]

what sort of filter layer?

[@Vlad-vk3mm]

I support this idea, I think he should go further with this! Maybe that will inspire some manufacturer to actually go to market, people don't care that much about thickness or consumption as companies may think.

[@b00marrows]

Maybe seeking a pair of LCD panels, one with and one without a filter layer might be a better goal to begin with.

[@BikeRaceOnly]

@@b00marrows Or maybe just peel off polarising layer.

[@tokiomitohsaka7770]

Professional dual layer LCD monitors use a monochrome LCD as the rear panel, which is better for light to pass through, thus increasing the efficiency (though it is still significant less efficient than a single layer LCD). Also, with your method, you are significantly increasing the saturation, so you would need to get a calibration device to counter that. Still, this is a really cool project!

[@1337Shockwav3]

Pretty smart idea to separate luminance and chrominance layers, rather than going with the QLED/rough zone lighting approach.

[@SergeiSugaroverdoseShuykov]

too bad there's no actual market with monochrome LCD's and conversion of colored LCD into monochrome one is nearly impossible task

[@tokiomitohsaka7770]

@@1337Shockwav3 I think that both are good for different purposes and budgets. The dual layered LCD monitors are designed for professional colour grading (especially for HDR) in high budget studios. QLED are great for other purposes, they are much cheaper, take less power, and are thinner. Mini-LED backlights are also gaining popularity, though they suffer from blooming. Personally, I don’t mind a bit of blooming as long as I am not in a dark room since I am not a professional filmmaker. I think this technology would be great in the hands of radiologists, but since medical diagnostic displays take a lot of time to be approved, this could be a while… though I think an OLED one specifically engineered and calibrated for medical imaging with an active cooling system would be the best. Edited: corrected.

[@Blox117]

oled will be cheap in a few years

[@NiMareQ]

Could he not use grayscale on the second screen? I know it technically still uses RGB components, but at least they would all get dimmer in proportion.

[@desi_bhai_]

i think removing the polarisation filter from the back lcd will help with brightness and eliminate the need of the tracing paper, you can then also bind both of the screens with uv glue used for screens, so there will be less blooming and blurryness in text

[@aBrokenShard]

I was thinking the same thing....removing one of the filters would do the trick.

[@grahammartin8568]

Me too, but what do I know. It would make the job easier and better if it worked

[@bozilla9975]

It won't work. The front layer of the back lcd and the back layer of the front lcd are 90 degrees apart in terms of polarization, so it would still completely block the light, unless you can find special LCD panel pairs which are oriented 90 degrees apart.

[@crystalsoulslayer]

This seems like it would intuitively make sense, but I did some research and I don't think it would work. The liquid crystal film doesn't block much light. It's just red/green/blue translucent goop, organized into subpixels that can be polarized based on how much of that subpixel's color we want to shine through. Without the polarizing filter, the backlight shines through all the subpixels all the time, and it's almost impossible for our eyes to resolve an image. You can find video of what LCD screens look like without the filter, and they're basically just bright lights. Actually, I think this channel has done videos about upcycling broken LCD panels into lightboxes for exactly this reason. With only one polarization filter, it'd be the same problem as before -- not being able to block enough of the backlight to get the nice inky blacks and high contrast.

[@acters124]

@@crystalsoulslayer How about getting a SLIGHTLY CLEARER polarizing filter that matches the second panel orientation?. I feel like he didn't explore this option enough and just brute forced the problem

[@decb.7959]

Something you didn't mention is that you have essentially doubled the display's gamma by multiplying all colors by themselves. Most displays have a built-in gamma of 2.2, but this raises that to around 4.4. You should be able to compensate by halving the gamma in software or in the monitor's settings, which will give you more accurate colors and fix over-saturation.

[@SreenikethanI]

same thought

[@bobsteven2363]

it would not be 4.4 since gamma is not on a linear function. More importantly, gamma does not describe the color saturation, it is instead a measurement of the luminosity of the pixels. We could assume that the gamma should actually be set higher than 2.2 because the overall luminosity has dropped with the combined LCD screens. As for color oversaturation, color saturation is also not on a linear function, and each color has a different curve. Meaning that each color acts differently on the same brightness, and colors even have different saturation changes with the same brightness change. And to top it off, since the contrast is being changed as well, the color saturations are changed even more. There is no way to calculate the required settings on your monitor. Which is why I'm sure he used a colorimeter like every youtuber out there to calibrate the monitor

[@KenTheSteak]

@@bobsteven2363 Your fun at parties huh?

[@bobsteven2363]

@@KenTheSteak I’m no fun at parties because I attempted to correct someone who is wrong? Do you believe people who are wrong shouldn’t be called out? That’s what Karens believe, and Karens aren’t fun at life

[@KenTheSteak]

@@bobsteven2363 I asked if you was fun, never said you wasn't, but thank you for answering, although I didn't ask "tell me you don't have friends, without telling me you you don't have friends"

[@ibayodeperegrino]

would be pretty interesting to test the optimised final version with an screen calibration tool, just to see actual numbers of things like nits, peak brigtness, color saturation, gamut, etc...and compare them with standard monitors

[@firdaus5093]

srgb and adobe rgb too!

[@qbzerodp]

@@firdaus5093DCI-P3 too

[@larryerb]

I need very high brightness for outdoors

[@Harsha04120]

Couldn’t you have removed the polarizer from one of them?, or am I just stupid? 😭

[@Mistlemon36]

THATS WHAT I WAS THINKING

[@ParotandArmorfinish]

This is a project that I think deserves a version 2. You might get better results with different panel technologies (like TN VN and IPS), or you might be able to dig and find better solutions for diffusion, polarization, backlighting and driving the displays. Even if the final result is expensive and impractical I think it's worth it to see just how much is possible by going full DIY.

[@fss1704]

He should just remove one polarizer off, i'm not sure wich but it should improve the image if done right.

[@djayjp]

VA panels ftw

[@JJayzX]

@Felipe Siqueira even if not removing one you can just get another polarizer sheet and rotate until it's corrected. Using paper for diffusion and polarizing is what kills this screen.

[@Wilson84KS]

Yeah, absolutely, first of all because fine working monitors are filling the landscape, they are like everywhere, on every corner, so in terms of real economic behavior, not in terms of money, it definitely not just deserves, but needs further experimenting, there is a lot of tweaking that can be done that will make the result much better, like removing everything from the actual LCD panel would need much less light, what we need here are only the black pixels that are amplifying the darkening effect. Thank you for the comment, saved me an own one which much less people would see.

[@nikoraasu6929]

@@djayjp worst panel

[@TheDarthShader]

One thing I think you might have missed is the gamma. Monitors are non-linear with respect to their input, and there is typically a compensation curve (gamma) to fix that. However, with two screens, your nonlinearity will be doubled and you will need to adjust your gamma curve (easily accessible in desktop OSs).

[@dorbie]

Yes, although not so easily calibrated and you can run into precision issues with the required exponent of 4.8 that he now needs instead of the more typical sRGB exponent of around 2.2.

[@displaytalk]

You will just have to hardware calibrate the end result. Might be easier if you calibrate both monitors before the sandwiching

[@jameshogge]

@@dorbie Really, this sort of display should be driven with different images sent to each monitor for this reason. It's got 16bpc in total at the higher gamma which could be remapped to the standard 8 (or even 12) with reasonable precision

[@dorbie]

@@jameshogge That would take a lot of highly refined calibration and systems integration that isn't really feasible in this context, it can buy you more bits but not 16 bits without independent backlights and a degree of control that doesn't exist here. You can do better than this though for sure. See my own response elsewhere and my referring to "esoteric reasons" for setting different display gamma values on each. Something that is feasible and easily within reach (if supported).

[@jameshogge]

@@dorbie The calibration needn't be too hard: you can do well enough by assuming that the individual LCDs are correctly calibrated. The rest is just maths with the light intensities. One of the groups at my uni did a similar setup with a DLP projector as the backlight for an LCD. But yes, it is a pain to then drive the displays. Ideally, you use an FPGA. Alternatively you have to set up a virtual display in Windows and write a couple of shaders to produce the actual outputs.

[@Benlucky13]

Love seeing these diy projects that compete with hardware 10x the price

[@erikhendrickson59]

To be clear, this is not going to "compete" with mini-LED & OLED tech. Mini-LED displays get MUCH brighter and while this may match OLED brightness, it will fall short and in pixel response times and input lag. Youre also driving two displays off of a single output, so you're gonna need one hell of a GPU

[@adamashworth6293]

@@erikhendrickson59 Nah it will be comparable to just driving a single screen in terms of GPU power if you use the "duplicate this display" option in windows.

[@giuseppevgiordano]

@@erikhendrickson59 hey, watch the video before writing, you don't need a "hell of a GPU", duplicating the signal is enough, and even if you tried running both out of the GPU mirroring monitors is one of the simplest things GPUs do, it's the same thing twice, it doesn't have an overhead at all, people that make GPUs are some of the smartest people on the planet. Please stop thinking that just because you don't see a solution for something no one is capable of doing it

[@hundvd_7]

@@erikhendrickson59 GPU power is going to be the _exact_ same as with one monitor. But you are absolutely right about the brightness, and the power consumption is also absolutely crazy. It's not a viable product because of these

[@hundvd_7]

@@adamashworth6293 The HDMI splitter he's using means the PC only ever knows about a single monitor. The GPU is doing 0 extra work, because it doesn't even know the image is duplicated

[@jonmayer]

Removing the polarizing layer would probably yield much better results, but I know it would be far harder to do without damaging the LCD. It would be cool to see you do it though, as I think you have the skills to do so.

[@fss1704]

Hot airgun and acetone, plus molybdenium wire used to separate touch on phones, that's easy if you ask any cellphone technician, just that when we do this by mistake it's a fking loss of a screen.

[@LokiScarletWasHere]

Removing the polarizing layer from one of the panels would likely raise the brightness floor and lower the contrast, though. The fact the two LCD panels resulted in black without a depolarizer in between indicates their output is polarized in perpendicular directions.

[@michaelrusso9809]

@@fss1704 I've partially pulled off the polarizing layer on a phone LCD by accident and managed the rehabilitate the screen by simply cleaning it off and reapplying some fresh self-adhesive polarizing film on top before. It's a royal pain in the ass, but it's not a total loss.

[@sunday87]

They could maybe just have flipped around one of the panels front to back. But then they would have to add signal processing to mirror one of the hdmi signals

Front to back could work just by coincidence. What you want here is rotate the panel by 90 degrees. Better option though is to buy different panel with the same pixel layout that already runs on different polarization. Both vertical and horizontal are in use, just have to check which monitor does what. That happens even between minor versions of the same model. I had two Dell screens that were almost identical, sam layout, same size, resolution, look almost the same, one was just newer year model. They had different polarization , so when I was wearing driving sunglasses, I could see only one of them. Besides that, there are multiple types of LCD panels. They generally work by rotating polarized light with liquid crystals and blocking unwanted part. Liquid crystals are usually used to change light polarization, not filter it. So they either rotate and block dark pixels or rotate and let through the lit pixels. The one we can see here is the latter type as the output has rotated polarization. You can also buy the former type and those can be simply stacked with no additional effort. That's because the light that should go through is untouched and the light that should be blocked is rotated to be blocked by filter. This would be a perfect screen. IIRC it's more often used by VA or TN panels, I don't remember details.

[@EvanBoldt]

I think you could actually add a middle polarization layer between the other two. Weirdly, if the middle layer is at an angle between the other two, it allows light to pass through all three. I think this would actually allow more of the original light through than paper.

[@stellabckw2033]

this!

[@melty4204]

"Weirdly" is an understatement. The fact that this works seems to defy all rational. like some kind of glitch in the matrix.

[@RaxXxvell]

@@melty4204 Wasn't it that if you consider the polarized light coming through as a vector, the vector gets projected on the next layer so that if you have a 90 degree angle, the projection result is 0, but if you project it 2 times on a 45 degree angle, it isn't 0, which means that light still gets through.

[@techman8817]

He could also flip over the second lcd, that should be the correct polarizations.

[@ikannunaplays]

If he took apart the panel stack and then stacked just the actual LCD's and then added the lens layers to that stack from one display in then he wouldn't need any of that nor the additional LED lights. The LENS layers serve multiple purposes and depending on the construction the polorizer often isn't affixed to the actual LCD and is just one of those layers in the LENS stack. On some panels it's glued directly to the LCD, but if it's not, then you can just stack the actual LCD's and place one stack of filter layers and that would eliminate all the Extra stuff he did with the paper and LED's. Note: When working with LCD panels films and lenses use gloves that leave no residue and do this in a dust free room while wearing something over your head or you will forever see dust, hair, and fingerprints on the image of the screen.