Would PureXP potentially work on OLED displays?

[Baron of Sun]

Hello there,

I‘m aware of the motion blur reduction benefits of PureXP in monitors like the ViewSonic XG2431. Actually I‘m just waiting for a 4K OLED display with HDMI 2.1 with at least 120 Hz refresh rate to use it for consoles like PS5, Switch and probably their successors.

As PureXP works with backlight strobing, I’m wondering if it could work in a similar way on OLEDs, as their pixels are self-lit. Is it possible to adjust the pulse width of a single OLED pixel refresh to get the same result as adjusting the pulse width of the full backlight of an LCD?

If that does not work on OLED, are there any other solutions coming in the next few years? From my understanding, BFI on OLED only puts in whole black frames, is that correct? So to get 1 ms MPRT one would need a OLED BFI with 1000 Hz (1 ms input frame and 999 black frames)?

Thanks in advance for clarifications to my question, if you know what I mean.

[RealNC]

It is possible, and it is being done through BFI. Every other frame is a black screen. However, pulse width is fixed that way. The black frame lasts for one whole refresh duration. At 120Hz BFI, the screen runs at 240Hz with half the frames being black, and each visible frame is shown for 4.2ms. There is no way to change that. It's the nature of BFI. There's some OLED monitors out there that have BFI. I have one, and 120Hz BFI has about the same motion blur as 240Hz without BFI. Which is to be expected with a "pulse width" of 4.2ms.

A better method is "rolling scan." This is very similar to how CRTs scan out the frames, but it also allows something similar to pulse width adjustment. With rolling scan, a horizontal bar scans out the whole frame from top to bottom, and everything outside that bar is black. Adjusting the height of that bar is the analogue of "pulse width." Another benefit of rolling scan is that your refresh rate isn't halved. 120Hz BFI needs the display to run at 240Hz, for example, and 240Hz BFI isn't possible (the display would then need to run at 480Hz.) With rolling scan, you get the native refresh rate. If you use 120Hz rolling scan, the display stays in 120Hz mode, it doesn't need to double it, and thus it's possible to use it even at the monitor's max refresh rate.

Unfortunately, I don't think any OLED monitor has this. They only have BFI. There has been an OLED monitor many years ago that did rolling scan, but it was not a gaming monitor IIRC.

I suspect rolling scan isn't implemented on OLED monitors because the brightness would be too low for many people. I don't know if there's OLED TVs though that do rolling scan (TVs are usually much brighter.) It's a bummer though that we aren't seeing rolling scan on OLED monitors. Some people are fine with low brightness.

[Baron of Sun]

Thanks for your reply and your explanations!

Rolling scan sounds like the ideal solution for that. Is it technologically too complicated to be implemented or is there just to small demand on that feature so manufacturers don’t care about it?

I’d be fine with low brightness as well. Motion clarity most often wins for me. I always ran my LG C1 with BFI high when playing Switch and I even sometimes preferred it for PS5 over VRR even though I had screen tearing then.

Apparently there must be reasons why manufacturers chose BFI over rolling scan, because the dip in brightness should be the same for the same motion clarity both technologies achieve. Any ideas on that?

[RealNC]

Rolling scan sounds like the ideal solution for that. Is it technologically too complicated to be implemented or is there just to small demand on that feature so manufacturers don’t care about it?

Rolling scan is not complicated or difficult at all. I suspect there's two reasons they don't do it. First is the brightness issue, second is that monitor vendors simply don't care much. We've seen the latter with other things as well, like complete lack of variable VRR overdrive with the vast majority (99%) of LCD monitors that don't have a g-sync module (overdrive is implemented by Nvidia in that case, not the display vendor,) lack of upscaling options (like integer scaling,) lack of good (or at all) sRGB clamping options, etc, etc. It's almost as if display vendors simply slap something together around the panels they source, put some RGB on it, and sell it

Anyway, there's a thread about rolling scan here, with some insights by Chief:

viewtopic.php?f=7&t=3388

[Baron of Sun]

Thanks for the link. Is the ViewSonic XG272 a potential candidate for my needs? Some say it has BFI with adjustable pulse width, but it is not Blurbuster approved and there is not much information on that? Any infos on that?

[RealNC]

Thanks for the link. Is the ViewSonic XG272 a potential candidate for my needs? Some say it has BFI with adjustable pulse width, but it is not Blurbuster approved and there is not much information on that? Any infos on that?

There's a thread about this monitor:

viewtopic.php?t=13268

[Supermodel_Evelynn]

BFI on OLED is a useless feature because it's so dim the cons outweigh the pros.

No amount of MPRT gains can ever compensate for the loss of picture quality due to dim screen when BFI is enabled on OLED.

Unless maybe you are willing to operate it in a pitch black room but even then you lost a LOT of picture quality from the lack of brightness

Notice how Viewsonic has a blur Buster 2.2 OLED but you never heard a word from Chief about it?
He probably realized it's not really worth it at this point in time.

[thatoneguy]

BFI on OLED is a useless feature because it's so dim the cons outweigh the pros.

No amount of MPRT gains can ever compensate for the loss of picture quality due to dim screen when BFI is enabled on OLED.

Unless maybe you are willing to operate it in a pitch black room but even then you lost a LOT of picture quality from the lack of brightness

Notice how Viewsonic has a blur Buster 2.2 OLED but you never heard a word from Chief about it?
He probably realized it's not really worth it at this point in time.

If you use HDR it’s decent enough.
One thing that’s been a misstep has been LG disabling 120hz BFI since their C2 model.

[RealNC]

BFI on OLED is a useless feature because it's so dim the cons outweigh the pros.

No amount of MPRT gains can ever compensate for the loss of picture quality due to dim screen when BFI is enabled on OLED.

For what it's worth, it's very bright for me. I don't use BFI much, but when I do, I don't even use 100% brightness but rather 80%-85%. (35%-40% without BFI.)

[Supermodel_Evelynn]

uuh noway

I want 500 nits for nice colorful gaming

It's true that brightness on OLED is far more efficient than LCD tho so it doesn't need as much brightness as LCD but glossy OLED needs that extra brightness for reflection handling.

In daylight BFI is a total NO NO far as I am concerned

We have never ever had a real replacement for CRT, companies should have tried to continue R&D on it and kept developing it and I am sure eventually weight and price would have come down.

Abandoning CRT has been the biggest crime against humanity since WW2

Look at how pathetic humanity is, fighting for basic strobing functions without all the garbage cross talk in 2024 to replicate something that has been available since the 1950s