With OLED you're going to have the TV producing Step 0 black, which has never been available, with artifacts being produced (mostly blockiness within the black areas) at higher steps, say 3,4,5. Due to the fact that you have contrast between those levels of black only fully visible on OLED, you can see them in the form of noise. Most LCDs and plasmas start at step 3 black and above so there is barely any contrast within the artifacts/noise so you can't really see them (but its definitely there, just watch walking dead or any HBO show and get up close to your TV and you will see it).
No, the OLEDs actually have less gradation near black.
Last year I think it was something like 6-bit precision people were measuring near black on the OLEDs.
When you displayed a 10-bit gradient you could see that there were fewer steps the closer you got to black.
This year it's better, but not fixed.
http://www.hdtvtest.co.uk/news/oled55e6-201604274285.htm said:
The 55E6′s near-black gradation was better than its predecessors, injecting a more palpable sense of dynamism and solidity to low-light detail. Nevertheless, there were a couple of telltale signs indicating its still not quite on par with that seen on Panasonics inaugural CZ950 OLED TV. For starters, the E6Vs default [Brightness] position of 50 has been purposely set up from factory to crush some shadow detail so that most users wont pick up its near-black foibles. Once we raised [Brightness] to its correct reference value, we could see that the television was applying dithering to shadowed areas to better mask above-black blockiness.
For example, the Shanghai night sky at the beginning of Chapter 8 in Skyfall appeared noisier and more pixelated on the LG OLED55E6V compared with other displays we had at hand in our test room. However, its no longer a dealbreaker especially at normal viewing distance last years OLED models exhibited larger and more distracting macroblocks.
People made similar arguments when comparing early LCDs and Plasmas to CRTs.
"The TV is bigger and brighter, so that's why compression artifacts are more visible."
Nope, the problem is that the panels had limited gradation which makes these issues in the source much more visible.
A good 10-bit LCD with >10-bit processing is capable of nice smooth gradation all the way to black.
OLEDs are good but struggle near black. Plasmas had very limited gradation and banding/image noise/shadow crush was common. Even with Pioneer Kuros.
The second problem that step 0 blacks causes is that there is black crush. All prior content has been mastered on monitors with step 3 and above black so reference black is actually visible (on the monitor they're mastering it on), so its not absolute black.
That's not remotely true.
LCDs display every single step from 0-1023 in a 10-bit signal.
It's non-LCD displays which struggle with that.
This means that since reference black as always been visible then every step above reference black has aslo been visible to the people mastering the content. Problem is that OLED black is not visible, and the first few steps out of black are not visible either so you get black crush. Black crush can be defeated on OLED by turning up brightness but this makes the reference black a visible black so you loose absolute black, which people have a struggle loosing considering that is the draw that makes OLED superior. Hope this helps.
The issue with LG's OLEDs is "floating black levels" which was also a common issue with most Plasma TVs.
What happens is that if you set the brightness using a test pattern so that all near-black levels are visible, the TV will display true black on an all-black screen.
But when you display certain types of mixed contrast image on-screen, it causes the black level to raise and be non-black.
That's why LG are crushing shadow details out of the box - so that black remains true black when it "floats".