At the launch of its TV range 2020 during the CES of Las Vegas, last January, LG placed a lot of emphasis on the possibilities of gaming use of its OLED TVs, thanks to the presence to both AMD FreeSync and Nvidia G-Sync technology, which allow perfect synchronization between the frames generated by the video card, eliminating problems with delays, stuttering and frame tearing.

Many 8K, new wall-mounted OLEDs and 48 “for LG at CES 2020 [/HWUVIDEO]

Variable Refresh Rate: OLEDs are not optimized

Software support for Variable Refresh Rate works well, but according to some tests, also confirmed by the OLED-A ( OLED Association ) the hardware of the OLED panels do not best support VRR or VFR (Variable Frame Rate) technologies . By activating the dynamic refresh rate from the menu, in fact, problems were found on the of black and on the gamma curve , with a rendering of the darker areas washed out (while the advantage of the OLED is owner I the one to offer deep blacks). Problems of instability and flickering have also been reported, in particular on the OLED TV range 2019 by LG.

The explanation is to be found at the hardware level in the panel. LG’s OLED panels that equip TVs are born to operate at a fixed

refresh rate of 120 Hz at the subpixel level , with a fixed charge time of the pixels (which are active and emit light). Activating VRR forces the subpixels to operate at slower refresh rates, resulting in a longer frame duration, resulting in a overcharging of the pixels , which then emit light no longer respecting the original gamma curve. This overload occurs at all brightness levels, but is more perceptible to the human eye in the gray tones of the darker areas.

A solution, cited in closing of the press release from OLED-A, could be that of adopt gamma curves optimized for lower frame rates , in order to compensate for the overexcitation of the pixels and eliminate the problem.