I measured the brightness of both HDR10 and DV 50 % patterns and there is quite a difference. Main reason may be the tone mapping of the B6 but does these suppose to have same brightness because HDR10 is code 502 and DV is 512?
HDR10 105 nits 1000 nit level
HDR10 88 nits 4000 nit level
DV 140 nits
LG OLED 55B6V, Finnsat FST03PVR, Toshiba 1T HDD, Genelec 6010B, BK XLS200-DF MK2
JVC DLA-X35BE, PS3, Apple TV3, Yamaha RX-V383, Tannoy Mercury F2, Tannoy Mercury F1, BK Monolith