LG will today release a firmware update for its 2020 OLED TVs (BX, CX, GX, ZX) meant to mitigate the 'VRR raised black' issues that users have been experiencing together with PCs and consoles.
Raised blacks in VRR mode
Owners of 2019/2020 LG OLED TVs have been complaining about raised blacks and occasional flicker in VRR (Variable Refresh Rate) mode when the OLED TV is connected to a VRR-enabled PC or console like Xbox. It has been discussed on forums and FlatpanelsHD also examined the issue in our Xbox Series X review.
LG will today start rolling out a firmware update in the US and EU that "can mitigate some of the raised near black effects customers have experienced" on 2020 OLED TVs; BX, CX, GX, and ZX. The firmware will be released gradually, first on LG's support pages (US, UK), and come to more regions later, the company said.
Activating VRR on Xbox can raise blacks on both LCD and OLED TVs (LG GX in the photo). In Gears 5 you can use this scene from the first chapter: Activate/deactivate VRR on Xbox to see the difference. Photo: FlatpanelsHD
The firmware specifically introduces a new 'Fine Tune Dark Areas' feature lets the user manually adjust black levels in VRR mode. After installing the new firmware, you can find 'Fine Tune Dark Areas' from Picture > Additional Settings.
FlatpanelsHD has yet to test the new firmware so we cannot comment on the effect yet.
LG said that it is also planning to bring the feature to 2019 OLED models (like C9) but it cannot provide a timeframe yet.
However, the firmware will not fully eliminate the issue as it appear to be inherent to LG Display's (LGD) OLED panel, which is currently used in all available OLED TVs from all brands. The underlying issue is believed to be related to the gamma curve (luminance curve) relative to frequency.
- "Gamma for OLED is optimized and fixed for 120Hz by establishing a fixed charging time for OLED sub-pixels. VRR is used when the frame rate is less than 120 Hz. When the OLED TV uses framerates less than 120Hz, the gamma curve is inconsistent with the frame rate," the OLED Association explained. "Therefore, the lower frame rates results in sub pixels that are overcharged, causing flickering of dark gray images, which is noticeable for dark images rather than bright ones, because human eyes are more sensitive to low gray colors. LGD will likely solve this problem establishing multiple gamma curves optimized for lower frame rates."
Raised blacks in VRR mode also affect LCD TVs as advanced LED zone dimming systems must be scaled down or disengaged in VRR mode where the TV synchronizes its refresh rate in real-time to match the frequency output from the PC or game console. It is, however, less visible on LCD TVs due to the generally poorer black levels.
New VRR firmware for LG 2020 OLED
Firmware version number (EU and USA):
LG OLED55BX, OLED65BX: firmware ver. 03.21.80
LG OLED48CX, OLED55CX, OLED65CX, OLED77CX: firmware ver. 03.21.18
LG OLED55GX, OLED65GX, OLED77GX: firmware ver. 03.21.18
LG OLED77ZX, OLED88ZX: firmware ver. 03.11.40
The feature in 2020 LG OLED TVs is available in Picture > Additional Settings > Fine Tune Dark Areas