musaji...the JU7100 HDR is basically a remapping of perhaps a 100 cd/m effective, with the HDR highlights then stretched out to the max 350cd/m or so maximum achievable brightness of the panel. I typically watch my TV at backlight of 5 (100 cd/m), and when watching HDR, the backlight raises to 20, but unless there is extreme bright parts of a scene, the overall picture is similar to backlight of 5. The most annoying aspect of this HDR stretch attempt is that black levels at backlight 20 are horrible...it's like looking at an old TFT or ISP computer monitor, with black letterboxing and such glowing...a full black screen emits enough illumination to see my room if it was pitch black at night.
I am caibrated for SDR, and my settings with my Xrite come to
I did a custom color space, and best DE was at Color 55
My calibration requires gamma at -2 (negative 2) to achieve 2.2, otherwise, the JU7100's stock gamma after calibration is 2.0.
As for why does everyone love the JU7100? It is very slow, the apps take forever, but no one makes a 120Hz 40" 4K set anymore. My next TV will be whatever comes out in 40" that is 120Hz, and it will obviously have much better HDR and black levels! If I could be far enough away fro a 65", I would buy a top of the line LG OLED, but alas, I am distance/space limited. :-(