OLED vs FALD vs Edge-lit HDR

[e22big]

Lately, I have been revisiting these three video from Hardware Unboxed (which for had been my primary guide on monitor consideration altogether with Rting) and I can't help but notice that seem to be some discrepancy when it comes to the credit he gave when it comes to HDR performance based on FALD and Edge-lit monitor. 

 

 

 

 

 

On PG35VQ which has FALD, Tim (the host) mentioned that the panel has some excellent contrast in HDR mode which exceed 100,000:1 but in the single frame worst case where the panel local dimming system can't be utilised effectively, the monitor fall back to the slightly FALD-enhanced native contrast which is stil very high and better than most LCD monitor (4200:1)

 

Then he mentioned in XG438Q that the monitor only has Edge-lit and can't get as bright as PG35VQ (HDR1000 vs HDR600) so best case scenario fall much lower at 20,000:1 but the worst case contrast doesn't suffer much compared to FALD PG35VQ as the native contrast is 4,000:1 only slightly less than than FALD 4,200:1

 

And lastly, he mentioned the Samsung G9 which is also HDR1000 but edge-lit. However, it can produce the best case contrast of 100,000:1 the same as FALD (it can turn off the backlight completely) but due to its edge-lit nature, the best case scenario is rare and the display only have 2,000:1 native contrast which make the HDR content looks poor.

 

Judging from these 3 seperated occasions, it doesn't seem to me that having an OLED (which from my understanding, also produce 100,000:1 in practice on best case scenario but  4,000:1 in worst case due to its poor near black performance) or FALD is an indication of a good HDR performance, they seem to have the same best case and worst case performance if the monitor can get bright enough, have a good enough native contrast and have good a enough local dimming system. 

 

Is this a correct understanding? I have personally seen OLED, FALD, and Edge HDR and honestly I can't tell the different between the 3 (outside of some scene trailer spesfically for OLED like the LG star demo.) I got the feeling that with OLED or FALD you are more likely to hit the best case scenario more often but then again, most scene in game rarely made use of a pitch black scene (it's video game afterall, if it get too dark then you aren't going to see stuffs) 

[Chris Pratt]

OLED has individual pixel control, whereas FALD has some number for dimming zones. With enough zones, you can get perceptibly close in HDR performance, but it will never be as good as OLED. Even at 1440p, you've got like 2.5M pixels being lit by at most thousands of zones with FALD. That's still coarse control.

[e22big]

22 hours ago, Chris Pratt said:

OLED has individual pixel control, whereas FALD has some number for dimming zones. With enough zones, you can get perceptibly close in HDR performance, but it will never be as good as OLED. Even at 1440p, you've got like 2.5M pixels being lit by at most thousands of zones with FALD. That's still coarse control.

How much of those can be translated into a practical benefit though? 

 

Correct me if I am wrong, but if OLED near black performance is around 4,000:1 then the fine pixel control shouldn't be that different from LCD (as they can change individual pixel colour to black and archieve the same fine contrast control result without local dimming - provide that the scene does not demand a pitch black colour) 

 

Not to discount the performance of OLED (I am fairly happy with the LG CX performance) but in term of practical effect in films and games, these are quite difficult to identify for me. At first I thought it would be all about halo effect but I haven't seen that either in both Edge and FALD monitor/TV

[SolarNova]

Near black contrast is precisely that .. near black, as such contrast ofc wont be as high as if u measure absolute black vs absolute white.

 

FALD fails where any given zone has predominantly black/dark content with a single or a few very high brightness points. In these circumstances the backlight is off or very low brightness, resulting in loss of detail of those few spots that should be bright.

The classic example being a space star field, where FALD, simply fails and you loose detail or  u have bloom when the zone is active. Meanwhile an OLED will not fail and will in fact excel in these circumstances.

 

There are a few very specific circumstances where the CX OLED 'very' near black can have issues with chrominance overshoot however the newer C1 has improved on this issue.

 

Examples:

 

[Chris Pratt]

2 hours ago, e22big said:

How much of those can be translated into a practical benefit though? 

 

Correct me if I am wrong, but if OLED near black performance is around 4,000:1 then the fine pixel control shouldn't be that different from LCD (as they can change individual pixel colour to black and archieve the same fine contrast control result without local dimming - provide that the scene does not demand a pitch black colour) 

 

Not to discount the performance of OLED (I am fairly happy with the LG CX performance) but in term of practical effect in films and games, these are quite difficult to identify for me. At first I thought it would be all about halo effect but I haven't seen that either in both Edge and FALD monitor/TV

Not sure exactly what you're talking about here. Contrast ratio is kind of BS. It's just the difference between the brightest part of the screen and the darkest, but that tells you nothing really. OLED displays actually claim an infinite contrast ratio because they can do pure actual black (off), which is a divide by zero thing. Literally any amount of brightness is infinitely brighter.

 

As for not seeing the halo effect with FALD or especially edge lit displays, I can only surmise that you're half blind and need to go see an opthalmologist post haste. That's easily detectable in anything with less than the thousands of zones in mini LED, and even then, it can be seen in a dark room or if you look closely. No monitor has a screen approaching that, and you definitely can see halos around cursors on even the best FALD monitor displays.

 

As long as the content is fairly neutral (not a very dark scene with bright spots, like a cursor or text), then yeah, it's not noticeable, but that's never been the issue. The problem that's being solve for with all this tech is dark area detail.

[e22big]

15 minutes ago, Chris Pratt said:

Not sure exactly what you're talking about here. Contrast ratio is kind of BS. It's just the difference between the brightest part of the screen and the darkest, but that tells you nothing really. OLED displays actually claim an infinite contrast ratio because they can do pure actual black (off), which is a divide by zero thing. Literally any amount of brightness is infinitely brighter.

 

As for not seeing the halo effect with FALD or especially edge lit displays, I can only surmise that you're half blind and need to go see an opthalmologist post haste. That's easily detectable in anything with less than the thousands of zones in mini LED, and even then, it can be seen in a dark room or if you look closely. No monitor has a screen approaching that, and you definitely can see halos around cursors on even the best FALD monitor displays.

 

As long as the content is fairly neutral (not a very dark scene with bright spots, like a cursor or text), then yeah, it's not noticeable, but that's never been the issue. The problem that's being solve for with all this tech is dark area detail.

 

See for yourself, this is the edge-lit monitor I recently got, did you see any halo?

 

My experience with FALD is the same as this, if there's any I haven't seen it. 

[e22big]

On 6/8/2021 at 8:19 PM, SolarNova said:

Near black contrast is precisely that .. near black, as such contrast ofc wont be as high as if u measure absolute black vs absolute white.

 

FALD fails where any given zone has predominantly black/dark content with a single or a few very high brightness points. In these circumstances the backlight is off or very low brightness, resulting in loss of detail of those few spots that should be bright.

The classic example being a space star field, where FALD, simply fails and you loose detail or  u have bloom when the zone is active. Meanwhile an OLED will not fail and will in fact excel in these circumstances.

 

There are a few very specific circumstances where the CX OLED 'very' near black can have issues with chrominance overshoot however the newer C1 has improved on this issue.

 

Examples:

 

Thanks, I've actually saw these video before but it's actually what got me wonder about the topic.

 

But then I saw his OLED vs QLED comparison and I think I understand the differences now 

[Stahlmann]

On 6/8/2021 at 3:52 PM, e22big said:

See for yourself, this is the edge-lit monitor I recently got, did you see any halo?

 

My experience with FALD is the same as this, if there's any I haven't seen it. 

The only reason we don't see any haloing is because all the zones are lit up. Haloing is what you see when a lit zone is next to a "off" zone. As soon as there is 1 white pixel in the zone, most edge lit monitor will just leave it on. That's the main reason why edge-lit HDR is just inferior. Just look at the local dimming test of the Odyssey G9 to see why edge-lit is typically regarded as useless dimming. It looks worse than if you would just keep all zones on all the time: Samsung Odyssey G9 Review - RTINGS.com (just ctrl+f and search for "local dimming", then watch the video).

 

And even with great FALD implementations you will lose details, because the dimming can just not be as precise as with pixel level light control.

In this video you can also see a few inherent issues regarding any form of local dimming, be it FALD or Edge-Lit:

 

I have never used FALD myself but i have a 27GN950 on hand that has 24 edge-lit zones and an C9 OLED which has pixel level light control for effectively over 8 million "dimming zones". The OLED is just superior in every way. Be it with measuring devices or my own eyes. I mostly just keep HDR off on my monitor, because it looks worse than SDR in most games.

 

It's technically impossible for edge-lit or even MiniLED monitors to get the same precise dimming as OLED. And when you're in a dark room, even the best MiniLED FALD displays cannot reach the fidelity of a mid-range OLED TV.

[VIVO-US]

Having experience with all of these different types of HDR, I can honestly say that Mini-LED FALD and OLED are the absolute best for contrast.  Edge-let dimming is awful, since it creates bands of light and dark across the entire screen, and FALD with standard LEDs is actually just as bad since there are only a few dozen LEDs to control zones (turned the feature off entirely on my old Vizio E series since it made the screen almost look defective).

 

Mini-LED FALD has a slight advantage over OLED in light scenes since it's able to get brighter, helping bright details to stand out more.  OLED has a slight advantage for darker scenes since it can actually achieve perfect black instead of near-perfect.