An Elite to Top Them All?
After the fall, many Pioneer video engineers, together with much of Pioneer's plasma technology, were acquired by Panasonic. But even though Panasonic makes outstanding plasma sets, it still has not reached the level that Pioneer achieved in its last year in one important respect: those inky blacks. Indeed, when the plug was pulled, Pioneer was only one or two generations away from the gold standardblacks that drop to total black when the source does. In a darkened room with such a set displaying a full black field, you would not be able to tell if the set was on or off. We may yet see such sets from Panasonic, but the question remainscan Panasonic replicate the black levels of the Pioneer Kuro sets and sell them at consumer-friendly prices? Pioneer could not (or would not) do this, and for that and other reasons, their video business slipped away.
In some circumstances, the best of today's LCD TVs with local dimmingthose that use full-array LED backlighting, not the more common LED edgelightingcan pull off that old black magic. Local dimming employs a number of LED zones, each of which can be individually darkened according the needs of the image in that area of the screen. Their effectiveness, however, varies with the number of zones and the sophistication of the processing that controls them.
But one intractable issue remains with any practical (i.e., affordable) number of LED zonesyou can't illuminate a small point of light against a near black background (like a streetlamp or a star) without some of the lighting spilling out into the dark area around the bright object itself. That leakage produces a halo or, as some refer to it, blooming. The latter term is borrowed from the olden days of the CRT. It meant something slightly different then, but its use now is also appropriate.
It is this issuealong with viewing angles and motion detailthat continues to make plasmas desirable, even though we have not yet seen a commercial plasma that can pull off the total black tricknot even those late, lamented Kuros could quite do it. Since plasmas are self-illuminated, each plasma pixel does its own "local dimming." Blooming is not an issue.
You're likely aware by now that Sharp has licensed the Elite name (though not the plasma technology) for use in its new line of flagship LCD TVs with LED local dimming. As reported here and elsewhere, these sets were officially launched at a New York press event last week. But I was not able to attend Sharp's press launch, as I'm based in Los Angeles, so my remarks here are no more definitive than those of anyone who has not yet laid eyes on oneor even those who may have seen the demo but have no way of knowing if the sets were set up optimally.
I doubt if the number of dimmable zones in these Elite sets is in the thousands, as some have speculated. We may be able to confirm or refute this at some point, though most manufacturers are reluctant to reveal how many zones their local dimmers use. At the 2010 CES, Toshiba showed prototypes of an LED-backlit set claimed to have something north of 500 zones, but it required the powerful Cell processor (of PS3 fame) to accurately modulate that many zones. Unfortunately, that line of Toshiba sets never went into production. The only local dimmer we know of with thousands of zones is a 47-inch SIM2, and that sells (mainly into the pro market) for several times the price of the 70-inch Sharp Elite.
Yes, the Sharps are expensive at $6000 and $8500 (60 and 70 inches, respectively). Only a close look will reveal whether or not these prices make sense in today's cutthroat video market and sluggish economy. But that last drop of video performance is always pricey. And as for the $2500 premium of the 70-inch model, LCD prices from most manufacturers tend to jump dramatically as the size increases. It's also hard to make a value comparison of any 70-inch set when there's so little competition at that size.
We haven't yet seen a local dimming set that didn't have some of that haloing or blooming. The best test I've found for this artifact is a star field, particularly the one that opens Stargate: Continuum. But fortunately, this type of scene is rare, and not all star fields, even some found later in this same film, exhibit the problem. Just as important for me is another test that reveals how well a local-dimming set handles the transition from black to near black. If it dims too quickly, it can squeeze out shadow detail and make a dark scene look crushed. If it works too slowly, some of the benefits of local dimming are lost as near-black areas of the screen become a lighter gray.
LED local dimming can do nothing to eliminate other issues found in many LCD sets, such as poor off-axis performance. But well-designed local-dimming sets are the current benchmark for LCD designs. Until some other technology such as OLED, carbon nanotubes, or something as yet unknown becomes both practicable and economically viable, local dimming remains the best that non-plasma sets have to offer.