Using local dimming LEDs, Sony KDL-46XBR8 gives a run at the title of best flat-panel ever. But does it take the crown?

The promise of local dimming LEDs is a simple one: significantly increase the contrast ratio of LCDs.
Using said technology, this Sony KDL-46XBR8 can create a near absolute black. So dark in fact, its contrast ratio is not measurable by standard test equipment. It can be called infinite. But that doesn’t tell the whole story.

Torch Mode Be Gone

First things first. When you setup the XBR8 for the first time, it asks you if you’re using the TV in a home or in a store. You’ll see more and more TVs ask what you think in the future. It’s a great thing, dialing back the settings so that it’s not as bright (and power hungry) in your home, where you don’t need it, than it would be in the store. It forces even the most neophyte of users to put their TVs in a setting other than show floor torch mode.

Processing is kind of a mixed bag. You’ll have to dig through the menus to find the “Full Pixel” mode; otherwise you’ll be getting overscan. Once enabled, you get every pixel in 1080i/1080p content.  

With video content, the XBR8 performs best with the DRC Mode off. Mode 1 is better for 1080i that was sourced from film (like watching a movie on cable/satellite), though there are still some artifacts. Mode 2 seems to get the 3:2 sequence perfect, but is made for 480i content, and can't be used with HD. The component input fares about the same with the processing tests as HDMI, but has slightly less horizontal resolution.

Scaling is good, with lots of detail pulled from 480i sources, and with no noticeable problems with 3:2 pulldown detection.

I turned off the Motion Enhancer as it interpolates frames to smooth out motion on this 120Hz display. I hate this feature on all TVs, though many others like it. So I’ll just say it's very "interpolatey" for those that like that look.

The image is a little noisy overall, but the onboard noise reduction set to Low works well without softening the image. There’s lots of detail, as you’d expect. Off axis performance isn’t great, about average for an LCD, at best.

The Real Story

Before we get buried in the details, let me first say that this is an excellent looking TV, but how good it may be needs a lot of explanation, especially when it comes to contrast ratio.

The black level, when fed a 0 IRE signal from DVD, is darker than can be measured by the standard tool of the trade, a Minolta LS-100. If you let your eyes adjust to the dark room, you can still make out that it’s on, but just barely.

So it is accurate to say that as far as the full-on/full-off contrast ratio goes, the XBR8 has an infinite contrast ratio, but this is merely a manipulation of the test.

That black level is impressive, but it is rarely, if ever, obtained while watching regular video. It’s like saying your Maserati does 185. Great, but when? 

When you put something briefly on screen, say the menu for a moment, after the menu goes away, there is a one- or two- second delay between when the screen goes from dark to merely black. It’s almost like the pulsing of a projector with an auto iris. This tells me that the absolute black that is possible with this TV is rarely seen on actual video.

For an objective measure of this, ANSI contrast ratio comes into play. This is a checkerboard pattern of sixteen white and black squares. In theory, this could trip up the backlight processing, or completely exonerate it.

If there were thousands of zones on the back of the XBR8 (an ideal) then the centers of each black box would measure the same as the full-on/full-off measurement. If there are fewer zones, then the centers of each box would be lit with a sort of bleed-over from being so near the white boxes and the result would be no better than a regular LCD.

The end result is somewhere in between. The most accurate way to test this is to compare the TV to itself, turning the local dimming (called LED Dynamic Control) on and off. In this case, the LED Dynamic Control results in a roughly 60% improvement in ANSI contrast ratio over the backlight set at a fixed level.

But as full-on/full-off was a false positive, the ANSI is in some ways a false negative. The 16-box ANSI checkerboard is a lot harsher than what you’d see with normal content.

The Most Objective is Subjective

With real content and LED Dynamic Control enabled, the contrast ratio is going vary per shot, ranging from the minimum (the ANSI contrast ratio) to somewhere near but not exactly the full-on/full-off contrast ratio, depending on what is on screen.

Compare this to a normal LCD whose contrast ratio remains roughly the same no matter what is on screen. LCDs with a backlight that adjusts as a whole don't change the contrast ratio within a shot, only between different shots. Each shot has the same contrast ratio, the backlight just adjusts so each shot has a different black level, but actual overall contrast ratio stays the same.

Even plasmas, whose light output is electronically limited (and therefore the contrast ratio decreases to some extent as the overall light output increases) the contrast ratio will be more consistent.

This per-shot contrast ratio change would only matter if you can see it actually changing. This ties in with the black level pulsing I mentioned earlier. For example, when the screen is black, and you hit the play button on your BD player, the little play logo lights up on screen—and so does nearly that entire half of the screen (just a little).

On the other hand, when credits roll up the screen, there is no “halo” as there are with other versions of this technology, though the overall black background is higher than if there was nothing on screen.

The only test, then, is with actual video material, and the eye will have to be the ultimate judge. The best example I found was with a disc with a lot of inter-shot contrast ratio itself, Batman Begins.

The result of all this local dimming effort is quite visible, but perhaps not exactly as you’d expect. The black areas of a given image aren’t too much darker than you’d see on a normal LCD, but the bright areas of the image are distinctly brighter. So the contrast ratio is definitely higher than a normal LCD. The image “pops” a lot more, adding a dimensionality to the image that most LCDs lack.

A Win?
    
The XBR8 is a fantastic looking television, with fairly accurate color points, decent (if not great) processing, and a contrast ratio that is considerably better than most other LCDs. It fact, it’s one of the best-looking LCDs on the market.

But despite what the numbers may suggest, the on-screen contrast ratio still isn’t to the level of the best plasmas. If the “p” word turns you off, then this is the first place you should look.

For a glimpse on what this TV looks like with just the LEDs on and the LCD layer turned off, check out the Sony portion of our CEATEC coverage (at the bottom).

DESCRIPTION
46-inch 1080p LCD with local dimming tri-color (RGB) LED backlight.

CONNECTIONS
Four HDMI inputs, one RGB-PC input, two component video inputs, one S-video input, three composite video inputs, one RF input, seven stereo audio inputs, one stereo audio output, one optical digital audio output, one LAN input, one USB port.

DIMENSIONS
29.125 x 49.625 x 12.5 (hwd, with stand)

PRICE: $4,999
CONTACT: 877.865.7669, sonystyle.com