Axiom Home Page Forums General Discussion Home Theater Still deciding on a new TV

I might as well follow up on what I have found and where I am heading with the quest for a new TV.

The OLED is just to costly so they are written off right away.

It seems that there are now two standards for 4K tvs. The common UHD and a newer SUHD. From what I have been told, the 'S' stands for a wider colour gamit and HDR. I know this was something brought up in another thread.

The expanded colour gamit is to meet the DCI P3 colour space that was defined in 2007 for the movie industry for digital movie recording. The project was to move all the movie projectors to the newer wide colour standard by 2013. This was the same time that film was to be completely phased out for movie viewing.

This is not to be confused with colour bit depth. Right now most TV's use 8 bits per pixel, so you can get 256 shades of each of the primary colours. The newer 10bits per pixel standard will increase the number of shades by 4x to a possible 1024.

But here is where the fun part of the display design comes into play. As LCD is a diminutive colour mask not an additive colour emitter, you require to have a back light shine through the LCD to see the picture. The original system for that backlight was a florescent tube in the back. This was replaced by more convenient LEDs thus we call them now LED tvs even though they are still realy an LCD panel.

There are now three main types of LED backlighting. Edge lighting that is pretty much putting multiple LEDs around the outside edge of the panel rather than a florescent tube. Direct back lighting, where you put a grid of individual LEDs across the whole of the back panel, or the newer FALD (Full Array Local Dimming) that is similar to Direct Back except the LEDs are arranged into zones and can be turned on and off to help with contrast and keeping darker areas darker as less background light needs to be blocked by the LCD panel.

This is where the rubber meets the road so to say, in that for TVs with the 10 bit colour and HDR to be able to display these, you need to have an ability to vary the background lighting so that the LCD can let the proper amount of light through. Currently Samsung only does the FALD lighting on their curved monitors and their flat panels are edge lit. If you don't want a curved TV then the HDR and 10 bit colour won't work properly.
Throw into the mix the different types of LDC such as TN, MVA, PVA, IPS ...) you can get into multiple combinations that some characteristics of the display will be great but others not so.

For example, LG uses an IPS panel, that has great off angle colour uniformity, but sucks with the contrast ratio and panel speed.


I ended up deciding on the Panasonic VIERA TC-65CX850 that uses a VA panel with the FALD back lighting. Has 10 bit colour and wide gamit but has not implemented the HDR (supposed firmware upgrade).