Originally Posted by jiopsi
I went from B8500 to C8000
I can confirm, C8000 has less haloing, what I have experienced.
A C8000 may indeed have less haloing if the dimming isn't really that active.
In such sequences it more or less resembles a non-LD set that does not have haloing at all. On the other hand you get exactly this:
The B8500 has overall better black level/ contrast ratio,
True LD increases contrast like no other LCD backlight type. A set with a relatively high amount of zones and intelligent control of them will *smoke* any type of edge dimming.
but in small area black level/ contrast C8000 takes the cake.
Local dimming *of course* has weaknesses - nobody denies that - and halos are perhaps the biggest problem of it. In consequence there are indeed occasions where a non-LD set will look better or subjectively better.
LD will however increase contrast compared with any other backlight type, provided all other factors are the same (same panel, same picture processing, same settings).
More detail on C8000 is true, and it is a big jump. But I don't really think it's because precision dimming.
I don't talk about "general detail" because it's heavily affected by the picture & motion processing and the better the processing the more details you see. This is especially true with motion processing and as there is still much room for progress and newer sets are often better at it (higher processing speed = better frame interpolation etc.).
However, as we talk about backlights, the only detail one should compare when comparing different backlights
is the "shadow detail" - which means detail in low brightness areas.
Older LD LCDs indeed suffer from "black crush" which results in loss of shadow detail because the appropriate zone gets dimmed too low. Even if the panel displays the exact pixel patterns in these dark areas you may not see them because the zone does not produce enough light to make them visible.
A classic example is a black night sky or space scene on the whole screen with only bright white stars all over it. There are three likely results:
- A non-LD LCD will, if you set the white to the correct level (and disable dynamic contrast) produce a non-black sky. The light spill is the reason for this as the LCD masks aren't yet perfect - if they were there would be no need at all for local dimming of any kind!
If you activate/maximize dynamic contrast the sky will become darker but the stars will also lose brightness. You may perceive this as a better image or not - but it won't be a true representation of the original image.
- An older LD LCD with a tendency for black crush will have a much improved black level and display a darker sky but less stars. Older sets "count" the number of active pixels per zone and if there aren't enough bright ones the complete zone stays dark.
- Other LD LCDs like for example the Sony XBR8 (or the European X4500 that I own) will display all stars at their correct brightness and thus have no black crush. The downside: The sky will be for the most part very similar to a non-LD LCD - grayish. Dark gray but not black.
So pick your poison - at this time you'll have to compromise in such extreme situations, but they are pretty rare in screen time. The overwhelming amount of video material will have less challenging scenes and true LD will be the best option as halos aren't that visible in them.
It's simple: LD will always be a better solution for a given panel until LCD masks are perfected to the point that no noticeable amount of light spill happens. Then LD will become instantly obsolete.
The question is: Will LCD masks get perfected before OLED or another new technology will make LCD as a whole obsolete?