The reason for that is they keep trying to make their flagship 4K and 8K sets so thin and have better viewing angles to compete with OLED, but it means the native contrast ratio is trash. Forget about the "with local dimming" value because thats meaningless with Samsung because they cheat the test patterns.
The Samsung QN90A QLED and the Samsung QN900A 8k QLED are high-end TVs in Samsung's Neo QLED series, which use Mini LED backlighting. While the QN900A is an 8k TV with a price tag to match, the 4k QN90A performs better overall. The QN90A has a higher native contrast ratio and a significantly...www.rtings.com
So you end up with more blooming/clouding because of the panel, no matter how many zones they have. The Q90A native contrast is trash compared to even a Sony XF90 from 2018/2019 which was a mid to high end set. The QN900A native ratio is embarrassing considering how much it costs, worse than the infamous Sony ZF9 and still not as bright:
Compare the Samsung QN900A 8k QLED and Sony Z9F TVswww.rtings.com
I love HDR on my ZD9, still blows me... away:
There is a general consensus that the Rtings review is wrong for many reasons but of course his measurement of the contrast with local dimming is one of them, even in Teoh's video review you twelve that with local diming the black level is practically zero.
Even so, it is enough to watch live TV, or if you prefer other measurements of other people to realize that it is wrong.
Maybe because Rtings use Calman that does not support this TV and can give you wrong readings, I don't know for sure
But there are many measurements since they do not match the Rtings measurements.
And above all reviews.
One of them