In filmmaker (HDR) mode on the 10% board, the maximum luminance at the beginning of the three-minute measurement was 1091 nits and within 180 seconds it increased to almost 1300 nits.
Unfortunately, although this is an excellent result, after three minutes the brightness began to decrease significantly: first to about 1000 nits, and then, i.e. five minutes after the beginning of measurements (i.e. after two minutes from the drops) it went down to 905 nits.
Interestingly, in the predecessor C4 there was no such drop, which indicates the possibility of overdrive by the engineers, i.e. deliberately overdriving the OLED panel.
Of course, this is possible only until critical conditions (temperature, current) are reached, after which the protection system automatically reduces the load on the panel.
On the full-screen white board, the luminance was 195 nits.