120Hz BFI returns for 2020 LG OLED lineup

[technick]

phpBB [video]

LG promised 120Hz strobing for their BFI solution in their 2019 OLED TVs, but unfortunately pulled it in the 11th hour and retail models were left with the same 50/50% 60Hz BFI with 8.3ms intervals.

Thanks to Vincent from HDTVTest it looks like 120Hz BFI is working once again and will be making its way into retail units. This is significant, as it should theoretically bring persistence down to ~4ms for 120Hz sources, while also enabling quality 3D playback as well. Good 3D generally requires BFI to give active shutter glasses time to transition, and it wasn’t functional with 60Hz BFI as it would drop every alternating frame of the 120Hz source. 3D isn’t officially supported of course, but now it should be easy to enable “Generic CRT mode” on the 3D Vision driver at 120Hz and get excellent 3D PC gaming with 120Hz BFI enabled. I’m sure I’ll only be one of maybe 5 people worldwide doing this, but it’s something I’ve been desperately waiting for.

It remains to be seen if the 4ms BFI interval carries over to 60Hz sources at single strobe, or if the feature actually makes it into retail units at all without being pulled again. Assuming the feature makes it, these LG OLEDs are truly a dream gaming display combining clean 120Hz BFI (instant response time should mean no crosstalk) along with Gsync Ultimate support with a 40-120Hz range confirmed, and even a more office/game room friendly 48” size option.

[AddictFPS]

LG OLED C9 (2019) Review

https://www.rtings.com/tv/reviews/lg/c9-oled

Unfortunately, like all OLED TVs, there is a possibility of experiencing permanent burn-in, and the brightness of the screen changes depending on the content (ABL), which may bother some people.

If this bright control limit continues in the CX (2020), is a big problem. At least i don't want random bright Up/Down.

I think is related to decelerate the Burn-In process, but is not optional, very bad decission. I prefer that LG say that warranty do not cover Burn-In, and notify user that disable ABL can accelerate Burn-In, but give user control over TV.

I have a doubt, whit BFI enabled (OLED Motion Pro) the Burn-In process decelerate ? Less pixel ON time, less Burn-In ?

OLED Motion Pro Levels: Off, Low, Medium, High

If CX with Motion Pro high + ABL Off set with low bright (120cd) can tolerate very good static images without burn, this can solve the big problem of use OLED to manufacture PC monitors.

Any info about this, can be very usefull.

[Kprime23]

Hi Technick,

Did you manage to get 3D Vision working with 2020 OLED's with Black Frame Insertion?

I'm almost there. I can see the upper half of the picture in perfect 3D, but it starts to show double image as it goes to the lower half of the picture. It seems as if the 3D vision glasses are not in perfect sync with the Black Frame of my LG CX 55 OLED.

[Chief Blur Buster]

Hi Technick,

Did you manage to get 3D Vision working with 2020 OLED's with Black Frame Insertion?

I'm almost there. I can see the upper half of the picture in perfect 3D, but it starts to show double image as it goes to the lower half of the picture. It seems as if the 3D vision glasses are not in perfect sync with the Black Frame of my LG CX 55 OLED.

You need to adjust the shutter timing a bit.

Does your 3D glasses have a shutter timing phase / delay / offset / shift feature?

Your glasses shutter is opening-up a smidge too early, there should be an approximately ~4ms delay added (halftime of a 120Hz scanout as seen in high speed videos of top-to-bottom refresh sweeps seen at www.blurbusters.com/scanout ...)

If this causes crosstalk to reappear at top edge when the bottom edge becomes clear, you'll want to try a ~2ms delay instead and live with clear center with crostalked top/bottom edge. You can also try to shorten the shutter-open duration, to get the widest crosstalk-free band possible.

For 120Hz 50%:50% BFI, there's too little safety margin to go completely crosstalk-free. One will need to wait for LG to use 2ms-MPRT pulses at 120Hz to allow a scanout-free blackness for 2ms, allowing full screen-height crosstalk free operation, since not all pixels refresh at the same time. The best you probably can do is get a clear screen-center with crosstalked top/bottom edges.

Currently, it's easier to use 3D glasses with global-flash LCD strobe backlights, than rolling-window scanned OLEDs that has no full-blackness guard time between refresh cycle sweepouts.