Originally Posted by hidefpaul
There seems to be some confusion in terms of wording used to describe LED LCD back-light systems.
Do not quote me on this, but I thought that "Direct Local Dimming" = a certain number of zones of back-light, where "Full Array Local Dimming" = a greater number of zones of back-light than direct. How many zones are required so that the FALD can be given to a particular set, I do not know. For example,the Vizio P series has less zones (64 total) than their R Series (384) , making the R series a FALD set.
There is confusion for sure (and some of it purposeful, no doubt), but I think you may be confusing 'zones' with LEDs...
'Direct-lit' is poorly worded to mean a smaller number of LEDs placed farther away from the LCD resulting in a thicker, less expensive panel. It can also imply lack of local dimming but that seems not to be consistent.
'Full Array' is also poorly worded to mean a denser array of LEDs which can be located closer to the LCD, so more LEDs than 'direct' and both 'thinner' and presumably more expensive.
'Dimming' of an LED backlight can be supported by either of these configurations as well as 'edge lit' and it is in the implementation of backlight dimming that 'zones' come into the equation.
l Dimming' ought
to have some meaning in terms of 'locality' so that the number of dimming zones is high and the size of the individual zones is small ('local'), but unfortunately it doesn't work that way and is fudgified all the time.
So the Vizio Reference Series with 384 dimming zones certainly qualifies as a 'true' Full Array Local Dimming panel (FALD), but Visio claims that their E-Series panel with only 16 (or fewer for smaller panels) dimming zones is also FALD. Edge-lit displays that implement dimming also claim that it is 'Local Dimming' even though there is no way to dim a zone that does not extend at least half-way across the screen when the backlight is edge-lit. For an example of this look at the Sony XBR-70X850B which is the subject of this thread - it has a:
'Dynamic Edge LED Backlight'
'Dimming Type: Local Dimming
' (unless that is a typo).
p.s. and you are correct, the Vizio P Series with 64 dimming zones, falls somewhere in between the 'true' FALD Reference Series with 384 dimming zones and the 'FALD-in-name-only' E-Series with 'up to' 16 dimming zones (and as few as 5 or 6 in some cases)...