Please be aware that Q7 black levels may vary over time. Yes, I know this thread is about Q9, but there might be some commonality with the Q7 model. I've never measured my 65Q7F, but my impression is that over a period of 3-5 days, what should be very dark parts of the picture, start looking lighter. Then, eventually, they get darker again. I find I can compensate by changing the Brightness control and the Gamma control down by 3 clicks during bright times, then back up during dark times. But of course this is a pain. Also, until I noticed the periodicity, it was very confusing.