I have been experiencing this dimming brightness issue that has been mentioned in this thread. This is on a 65A1E.
I mostly game on a ps4 pro and the HDR picture will look really good when first starting out, nice and bright, then in about 1 minute the screen will start to dim out over the next 5 seconds and remain dim until there is a complete change on the screen. Its like eco mode is being flipped on or extended dynamic range is being set to low or off. If you actually set XDR to low or off the picture looks just as dim as when this issue occurs. If you set extended dynamic range to low or off the picture does not seem to dim in either SDR or HDR modes. If you lower the contrast to 50 or below it doesn't seem to occur. But with the contrast or XDR so low the picture is already dim. This is also happening in SDR mode but to a lesser extent. Enabling BFI also displays this issue.
Eco mode is disabled. I've toggled the pixel shifter on and off and that does not affect it. The light sensor for brightness is disabled. Adv Contrast Enhancer is off. It's really noticeable when playing games on a ps4 pro in HDR. I've also noticed it start to dim out during HDR and DV content on the Netflix built in app but with this it seems to take a bit longer and it's more random to start dimming compared to gaming. This happens in the standard/custom/cinema pro/game picture modes, I have not tested all the other modes. I manually installed the 3.20.18 dated firmware the other day and then did a factory reset. Issues is still occurring.
When playing a HDR game like ESO and running a dungeon by the time you get done with the first boss the screen will be noticable dim. If you hit the home button on the ps controller in about 10 seconds the brightness is restored. You go back into the game, brightness is restored and it looks great again. Till it starts to get dim again in about 1 minute. You can also hit the the home button on the tvs remote, scroll around, and the brightness will come back in about 10 seconds to. If you do not intervene eventually the brightness will restore but it seems to take a complete change in what is on the screen in order to trigger it restore the original brightness. Like pulling up the map in a game, or changing areas. Then it will start to dim out again over the next minute.
I've noticed it in Farcry 5. You'll be running around playing the game and then all of the sudden you notice the picture is really dim. Almost like a cloud is covering the sun but its not. I've seen this same issue in Monster Hunter World, No Ni Kuni 2 and many other HDR titles. In MHW if your out in the field on a hunt you will notice that the everything gets much dimmer all the sudden. At the Ni No Kuni 2 title screen, which is a scrolling animated background, in about 1 minute the picture will become dim. In Gran Turismo Sport about halfway through a race the brightness is noticeably dim. It's almost as if the HDR part of the content is being removed. The image presented during this dimming doesn't look like a HDR picture.
I have friends that have various models of the LG oled and they are not seeing what I am describing when co-op gaming with them. I tested this on a regular PS4 and get the same issue. I am also seeing this happen with a Nintendo switch on another HDMI input.
This brightness fluctuation while viewing the A1E is highly annoying, immersion breaking and very noticeable to even a untrained eye.
Could this be some sort of Automatic Static Brightness Limiter kicking in? I dont think its the typical Automatic Brightness Limiter kicking in as its a gradual reduction in brightness after X amount of time and not an immediate change. I read that the LGs have a “TPC” setting that can be disabled in the service menu. I have seen no mention of toggling this type of function on a Sony. Is there something similar in the Sony service menu? Any other ideas as to what is going on?
Custom/Game/Standard Picture Mode - HDR and SDR
Auto picture mode - off
Light sensor - off
Brightness - max
Contrast - 90
Gamma - 0
Black Level - 50
Black Adjust - off
Adv contrast enhancer - off
Peak lumiance - high
Color - 50
Hue - 0
Color temperature - expert 1
Adv color temperature - defaults
Live Color - off
Sharpness - 50
Reality Creation - off
Smooth gradation - low
Motionflow - off
Video options - all set to auto
Eco mode - off
Pixel shifter - on
Screen saver set to 15 minutes on tv and ps4
Advanced HDMI enabled for ports 2 and 3
Display options are all set to auto on the ps4.
I've attached some photos that kinda illustrate what I'm seeing. Its not as obvious in the pictures as it is in person but you can defiantly see the difference in brightness between the two pictures.