some questions about OLEDs and BFI (Black Frame Insertion)

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blackoak
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some questions about OLEDs and BFI (Black Frame Insertion)

Post by blackoak »

I'm looking to upgrade from my 50" LCD Sony X900E, looking at a 75" OLED of some sort. Most of my gaming will be done through a MiSTER, and I'm curious to hear people's experiences with BFI on the latest models.

My understanding, having read a lot around the web (at the blurbusters forum especially), is that the LG CX has the strongest/"best" BFI implementation, reaching ~4ms persistence, but the screen brightness/black crush kind of makes it not worth it. That leaves me looking at the C1 and A80J for my budget.

In my memory, the 2013 Sony W900A I used to own had the best, most dramatic implementation of BFI that I've personally seen to-date... not quite CRT level, but good enough that I didn't care. It seems like the later implementations of BFI I've seen, such as that of the X900E, have been worse (in fact, I can't even notice a difference on the X900E when I turn on BFI... was there something special about the way the W900A did BFI??? Or maybe native motion resolution has simply gotten better...???))

So yeah, basically just looking for subjective thoughts/experiences on these models (LG CX/C1 and Sony A80J) or other left-field recommendations as they pertain to BFI/CRT-like motion. Here in Japan it's nearly impossible to return new TVs unless it's a product defect, so I have to be pretty sure about what I'm getting into before pulling the trigger. Thanks!
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tongshadow
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by tongshadow »

Since you're doing retrogaming on your Mister, get an LG. They can support a variety of oddball resolutions/refresh rates so you're less likely to run into problems using the Mister. LGs are also more game centered when compared to other OLEDs, which are mostly geared towards movie/TV viewing. I would personally get the C1 if I had to choose between OLED models.

If you value motion clarity, you should also consider Plasma displays, they still hold up pretty well despite their age. I'm sure good models are not hard to find in Japan for cheap, so consider this option as well.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by bobrocks95 »

Avoid the B2/C2 for retro gaming, as they have significant added lag in 4:3 picture modes that I haven't seen any confirmation was fixed with a firmware update. Hopefully the 3 series doesn't have the same issue.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by orange808 »

Make a plan and design your gaming room to control ambient light around your OLED. Low light is no problem with OLEDs, because the black levels are good. So, you'll only need enough light to make the flicker of BFI rolling scan tolerable. Avoid reflecting light off the screen and don't shine light directly in the eyes of viewers.

That's how you get things to be perceptually bright and employ BFI.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by Guspaz »

orange808 wrote:Make a plan and design your gaming room to control ambient light around your OLED. Low light is no problem with OLEDs, because the black levels are good. So, you'll only need enough light to make the flicker of BFI rolling scan tolerable. Avoid reflecting light off the screen and don't shine light directly in the eyes of viewers.
This is only true with WOLED panels. If you've got a QD-OLED panel, then their black level is directly correlated to ambient light and you'll definitely want to keep things as dark as possible. If memory serves, the speculation was that they lack a polarizing layer that would normally be used to stop ambient light from impacting black levels. I don't personally find it a huge problem in my setup with my QD-OLED monitor, but it's still a thing.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by Rastan78 »

blackoak, my impressions of BFI on thr LG C1 are really good. Maybe motion clarity is not quite CRT levels, but it's close enough to be quite a massive difference.

Brightness was not an issue for me at all. Comfortable levels of pixel brightness for normal use are between about 35 to 50 on a scale of 100 to my eyes. So plenty of room to crank it up and compensate for BFI. Of course people who want to maintain eye searing levels of brightness and/or have their setup in a very sunny room might think differently.

Note: you first have to mess around in the settings and disable an energy saving feature that will lock you out of adjusting pixel brightness on the LG.

Just know that you may be adding some input lag with BFI on so it might be better or worse to use it depending on the content. I would think with the mister you'll have some leeway to turn on BFI and still have things feel very responsive.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by Gara »

bobrocks95 wrote:Avoid the B2/C2 for retro gaming, as they have significant added lag in 4:3 picture modes that I haven't seen any confirmation was fixed with a firmware update. Hopefully the 3 series doesn't have the same issue.
Dang... I wonder if they really haven't fixed that yet. Chances of a fix go way down after about a year. LG is very quick to shift focus to new models. Losing LG OLED's as the goto for retro gaming on a modern screen would really be a lose.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by tongshadow »

Gara wrote:
bobrocks95 wrote:Avoid the B2/C2 for retro gaming, as they have significant added lag in 4:3 picture modes that I haven't seen any confirmation was fixed with a firmware update. Hopefully the 3 series doesn't have the same issue.
Dang... I wonder if they really haven't fixed that yet. Chances of a fix go way down after about a year. LG is very quick to shift focus to new models. Losing LG OLED's as the goto for retro gaming on a modern screen would really be a lose.
This is not a problem at all if you use PC sources or optimized 4:3 modes that output widescreen modes, like the OSSC's 5x 240p 1920x1080. For other modes like 2x 480p or 4x 480i, the additional 4:3 processing lag is so small that it doesnt justify getting an used model that's likely out of warranty and worn out.
I still think the C2 is a good modern screen for retrogaming when used with a good video processor, like the OSSC, due to its amazing compatibility with out of spec signals. Not to mention it's the only model available in a 42" size.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by bobrocks95 »

tongshadow wrote:
Gara wrote:
bobrocks95 wrote:Avoid the B2/C2 for retro gaming, as they have significant added lag in 4:3 picture modes that I haven't seen any confirmation was fixed with a firmware update. Hopefully the 3 series doesn't have the same issue.
Dang... I wonder if they really haven't fixed that yet. Chances of a fix go way down after about a year. LG is very quick to shift focus to new models. Losing LG OLED's as the goto for retro gaming on a modern screen would really be a lose.
This is not a problem at all if you use PC sources or optimized 4:3 modes that output widescreen modes, like the OSSC's 5x 240p 1920x1080. For other modes like 2x 480p or 4x 480i, the additional 4:3 processing lag is so small that it doesnt justify getting an used model that's likely out of warranty and worn out.
I still think the C2 is a good modern screen for retrogaming when used with a good video processor, like the OSSC, due to its amazing compatibility with out of spec signals. Not to mention it's the only model available in a 42" size.
To summarize the C2 problems MLIG had:
- Worse BFI options compared to CX/C1
- Additional lag for all 4:3 modes- affected would be RT5X's and Mister's 1920x1440p modes, OSSC 480i/p to 960p modes, raw 480p input from eg Gamecube/Xbox, and maybe some other 4:3 use cases.
- 1200p support from OSSC removed (that's what I use personally on my B9)
- Problems with SDR brightness compared to B7 (could be a fluke on this one)

4:3 + BFI hit 42ms of lag which is approaching unacceptable for a large number of people. That plus the fact that BFI options on the C2 were reduced to just an on/off toggle, and the OP is specifically asking about BFI on displays, means the C2 should be avoided for them.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by fernan1234 »

This is a good case for why we can't rely on the TV manufacturers to consistently provide a good solution to persistence blur both in terms of effectiveness, adjustability, and minimum lag. We need an external solution.

Let's pray Mike will figure out a way to add a retro-friendly BFI feature on the Tink-4K.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by cfx »

tongshadow wrote:
Gara wrote:
bobrocks95 wrote:Avoid the B2/C2 for retro gaming, as they have significant added lag in 4:3 picture modes that I haven't seen any confirmation was fixed with a firmware update. Hopefully the 3 series doesn't have the same issue.
Dang... I wonder if they really haven't fixed that yet. Chances of a fix go way down after about a year. LG is very quick to shift focus to new models. Losing LG OLED's as the goto for retro gaming on a modern screen would really be a lose.
This is not a problem at all if you use PC sources or optimized 4:3 modes that output widescreen modes, like the OSSC's 5x 240p 1920x1080. For other modes like 2x 480p or 4x 480i, the additional 4:3 processing lag is so small that it doesnt justify getting an used model that's likely out of warranty and worn out.
I still think the C2 is a good modern screen for retrogaming when used with a good video processor, like the OSSC, due to its amazing compatibility with out of spec signals. Not to mention it's the only model available in a 42" size.
The bolded part is a pretty funny comment coming from you given how any comments about much older plasmas being old and worn our are brushed aside by you in your plasma thread. :roll:
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by tongshadow »

bobrocks95 wrote::3 + BFI hit 42ms of lag which is approaching unacceptable for a large number of people. That plus the fact that BFI options on the C2 were reduced to just an on/off toggle, and the OP is specifically asking about BFI on displays, means the C2 should be avoided for them.
Can the MisTer benefit from 120hz BFI? If yes, then the older model is a better choice. But if the focus is on 60hz emulation then BFI performance should be very similar. The "High" BFI setting on older models is the only choice for 60hz, and it's equivalent to the C2's On toggle.
cfx wrote: The bolded part is a pretty funny comment coming from you given how any comments about much older plasmas being old and worn our are brushed aside by you in your plasma thread. :roll:
Plasmas are more durable, cheaper and still hold up visually compared to OLEDs. Find me OLEDs under 100$ that dont have noticeable degradation (none of them will have BFI anyways), and then you can try being snarky again :wink:
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by blackoak »

Just wanted to say thanks for all the advice here, I ended up getting a 77" C1. Very nice so far for both movies and games. I've not put it through the paces yet or done much optimization, but the BFI does feel strong enough to me, and similar to my old Sony 900W. Unfortunately the accompanying drop in brightness forces a compromise between that vibrant OLED color and CRT-like motion, so I've found myself turning it off and going with the "good enough" (really quite good) native motion handling of the OLED. No complaints so far though!

Am I right in imagining that 5-7 years from now, there may be "brighter" OLEDs which allow the best of both worlds? Or has OLED technology peaked already there...?
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by Konsolkongen »

blackoak wrote: Am I right in imagining that 5-7 years from now, there may be "brighter" OLEDs which allow the best of both worlds? Or has OLED technology peaked already there...?
The LG G3 with MLA can do roughly 1500nits, almost twice that of other OLEDs. MLA will probably be included in the C series in the future too.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by fernan1234 »

Konsolkongen wrote:The LG G3 with MLA can do roughly 1500nits, almost twice that of other OLEDs. MLA will probably be included in the C series in the future too.
Peak brightness on a small 10% window is not a really useful spec when it comes to this topic's purpose. Sustained full screen white brightness max brightness is what you want to know, since that's what you'll be working with as you then halve it for 60Hz BFI (and potentially halve it one more time if using filters for upscaled retro games).
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by Konsolkongen »

fernan1234 wrote:
Konsolkongen wrote:The LG G3 with MLA can do roughly 1500nits, almost twice that of other OLEDs. MLA will probably be included in the C series in the future too.
Peak brightness on a small 10% window is not a really useful spec when it comes to this topic's purpose. Sustained full screen white brightness max brightness is what you want to know, since that's what you'll be working with as you then halve it for 60Hz BFI (and potentially halve it one more time if using filters for upscaled retro games).
215 nits full field according to this video:
https://www.youtube.com/watch?v=VEnChcCQ2Dc

But that's only really relevant when watching a white screen. How much of your gaming is that really?
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by tongshadow »

Konsolkongen wrote: But that's only really relevant when watching a white screen. How much of your gaming is that really?
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by fernan1234 »

Konsolkongen wrote:But that's only really relevant when watching a white screen. How much of your gaming is that really?
A full white screen (or 100% window) is just how you measure max sustained brightness (at a given white point like D65).

And 215 nits means that with BFI@60 you're getting about 100nits which means you get a calibrated CRT, which is good, though will still look a bit duller than a CRT. And that means something like a full scanline filter is out of the question, unless you're okay with 50 nits.
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Re: some questions about OLEDs and BFI (Black Frame Insertio

Post by tr1f0rc3 »

fernan1234 wrote: Tue Jun 13, 2023 1:40 pm
Konsolkongen wrote:But that's only really relevant when watching a white screen. How much of your gaming is that really?
A full white screen (or 100% window) is just how you measure max sustained brightness (at a given white point like D65).

And 215 nits means that with BFI@60 you're getting about 100nits which means you get a calibrated CRT, which is good, though will still look a bit duller than a CRT. And that means something like a full scanline filter is out of the question, unless you're okay with 50 nits.
IIRC with the rt4k theres some hdr functionality that will recover a lot of the lost brightness back to normal, so gotta get that for bfi and filters while retaining acceptable, if not ideal nit level without having to shell out a ton of money for a G3.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by Guspaz »

Software BFI like the RT4K's drives the ABL on LG OLED TVs insane, leading to a rapid flickering/pulsing. I believe you can disable that behaviour in the service menu, but the RT4K's HDR brightness boosting is best used for scanlines and mask effects.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by VEGETA »

I've been reading about bfi and so on but came to my mind the question of why these modern scalers never implement true frame rate conversion technique?

like, if you want smoother movement with less blur your scaler (not the tv) can do the fps change to 120 and take care of intermediate frames and so on. many techniques are used to change fps not just this one but i bet they can figure out the best. some scaler chips provide such features.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by Josh128 »

Doubling the refresh rate induces both motion incoherency (2 strobes/scans per frame) and latency (half a frame at minimum) so it's not without tradeoffs. You can do motion interpolation to mitigate the former (remember the 100Hz CRT TVs) but that bumps the lag even more. That said, 240p 120+Hz output should be doable on the Pro model.
Marqs said a couple years back in the OSSC Pro thread that 240p120Hz output is doable and I think the unit currently does it. The question about 240p120 +motion interpolation was raised and I believe he said the Pro could technically do it, but it would add latency. Whether or not any digital flat panel would accept such a resolution is a different question.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by bobrocks95 »

Guspaz wrote: Wed Nov 15, 2023 5:31 am Software BFI like the RT4K's drives the ABL on LG OLED TVs insane, leading to a rapid flickering/pulsing. I believe you can disable that behaviour in the service menu, but the RT4K's HDR brightness boosting is best used for scanlines and mask effects.
Is that with BFI + HDR enabled on the Tink? Or just BFI at all? I don't think I'll be using it since I'm very sensitive to flicker, but it would be nice to at least mess with the BFI modes.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by Guspaz »

It only happens with you do both BFI and HDR on the RT4K at the same time. I believe you can reduce the RT4K HDR nits setting until the issue goes away, though at that point you've largely defeated the point of the HDR. I haven't re-tested this recently though.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by orange808 »

Interpolation latency depends on the algorithm. We already discussed that 240Hz takes about 4ms to travel up the wire. Native 60Hz takes about 17ms. A 240Hz refresh cuts ~12-13ms of latency out of the signal chain by sending the complete frame quickly (after it's buffered).

So, if the Tink4k used an interpolation algorithm based on one buffered frame and previous frames, the latency on your display will only be about 4ms slower than natively sending 60Hz to the display (plus whatever time the Tink4k would spend calculating the frames). Should be about 21ms on a zero lag display.

Of course, the quality of that approach might not be great. Even if you buffer two frames, it's still possible to get the new frame up the wire in 4ms. So, you still don't actually wait as long as you might expect; it can still be less than a full ~34ms you might expect to add, because you also have to wait an additional 17ms to send the frame. That brings the expected total to ~51ms. The fast 240Hz refresh would save ~12-13ms off that number, versus sending 60Hz up the wire. So, it's more like 38ms. Some people might still be okay with that. That's a lot less than what we see on most displays for interpolation.

I wouldn't use it for games. I would love to have an external video processor that could gently smooth out film content. That's something that many displays struggle with and it would be nice to shop for displays and not worry if the internal processing was Sony. I could buy anything I wanted and always have my film video processing ready in a separate box. I love things that break walled gardens. I hope it happens.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by Josh128 »

orange808 wrote: Fri Nov 17, 2023 1:50 am Interpolation latency depends on the algorithm. We already discussed that 240Hz takes about 4ms to travel up the wire. Native 60Hz takes about 17ms. A 240Hz refresh cuts ~12-13ms of latency out of the signal chain by sending the complete frame quickly (after it's buffered).

So, if the Tink4k used an interpolation algorithm based on one buffered frame and previous frames, the latency on your display will only be about 4ms slower than natively sending 60Hz to the display (plus whatever time the Tink4k would spend calculating the frames). Should be about 21ms on a zero lag display.

Of course, the quality of that approach might not be great. Even if you buffer two frames, it's still possible to get the new frame up the wire in 4ms. So, you still don't actually wait as long as you might expect; it can still be less than a full ~34ms you might expect to add, because you also have to wait an additional 17ms to send the frame. That brings the expected total to ~51ms. The fast 240Hz refresh would save ~12-13ms off that number, versus sending 60Hz up the wire. So, it's more like 38ms. Some people might still be okay with that. That's a lot less than what we see on most displays for interpolation.

I wouldn't use it for games. I would love to have an external video processor that could gently smooth out film content. That's something that many displays struggle with and it would be nice to shop for displays and not worry if the internal processing was Sony. I could buy anything I wanted and always have my film video processing ready in a separate box. I love things that break walled gardens. I hope it happens.
So has Mike actually said anything about motion interpolation being implemented in the 4K? You said you wouldnt use it for games, but an obvious use case where it would be quite cool would be to interpolate frames when frame doubling 240p60 content to 240p120 for use on 31KHz VGA CRTs. It would eliminate the "double strobe illusion" that presents when doing the 240p120 treatment on 240p60 source signals. To refresh, the whole reason for the 240p120 mode would for the far superior brightness and color pop vs 480p60 + artificial scanlines.

This is another edge use case of course, but if Mike wants the 4K to be the Lamborghini of retro scalers, which Im sure he does, these "edge use" cases can be very beneficial. The 540p mode that Mike so graciously implemented in the 5X after my requesting it has gotten quite a bit of traction and notoriety in the CRT community, even though its currently still relegated to an older FW. Mike had to choose between keeping it or adding even more cool new features so he obviously chose the latter with the caveat being that if someone wanted the mode, they could simply use the FW that supports it. On the 4K, it seems like he wont have much memory constraint and can add all kinds of cool things easily into the available memory without having to pick and choose what gets to stay and what has to go in order to fit.
Last edited by Josh128 on Fri Nov 17, 2023 12:26 pm, edited 1 time in total.
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Re: some questions about OLEDs and BFI (Black Frame Insertion)

Post by Guspaz »

There's no motion interpolation support. I don't believe there are any plans for it either? There are some processing settings that reference previous frames, usually stuff relating to interpolation.

As far as film content goes, there's the 3:2 pulldown support if that's relevant, and there's the ability to do multi-strobe BFI on 24Hz content to simulate a film projector (which used multi-bladed shutters which essentially strobed each frame 2-3 times). There's also various colourspace stuff you can do, and while it won't compete with something like NGU, the RT4K's able to do various levels of lanczos without ringing, which is nice.
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