Pioneer's Kuro: As Good As It Gets?
and its use by Pioneer refers to the low black levels its plasmas are claimed to produce.
I RECENTLY HAD THE OPPORTUNITY TO EVALUATE Pioneer's new 50-inch 1080p KURO plasma HDTV, Elite PRO-110FD. For those who don't know, “kuro” is Japanese for “black,” and its use by Pioneer refers to the low black levels its plasmas are claimed to produce. I first saw the Kuro products in the spring 2007 under tightly controlled viewing conditions: in a restaurant that had been draped off and had very little ambient light floating around the room. Even Pioneer execs were dressed in dark black and gray suits.
This was done for aesthetic and technical reasons. Aesthetically, the demonstration would be much more dramatic when saturated colors appeared amidst the black-to-dark-gray viewing environment. Technically, the minimal ambient light would allow members of the press to judge just how deep the black levels were.
The press event was quite a contrast (no pun intended) from previous events I've attended. There is no doubt that Pioneer is on to something — the pictures have inky black and deep, saturated colors, particularly reds and dark greens. The fact that these new plasma HDTVs come with 1080p resolution is just icing on the cake.THE PROOF IS IN THE PUDDING
Still, press events are just press events. The only measurements that ever matter to me are the ones I take in my studio, under controlled conditions, with the display set for best grayscale image quality. And that's exactly how I tested the PRO-110FD, using test patterns, full-screen primary and secondary colors, and luminance windows from black to white.
The results are quite impressive, and far exceed the performance of any plasma HDTV or monitor I'd tested to date. My previous record for lowest black levels was in the range of 0.15 nits, but the Pioneer unit blew past that with an average reading of 0.065 nits.
That in turn pushed average contrast levels with a 50/50 black/white checkerboard test pattern to 1082:1, and peak contrast within that same pattern measured 1523:1. The highest contrast reading I took was a sequential (small area white, then full black) reading and it came in at 2291:1.
To put this in perspective, the average and peak contrast numbers are 35 percent and 49 percent higher respectively than those I measured on Pioneer's first 50-inch 1080p plasma, the PRO-FHD1, in early 2007. The lowest black level that model could produce was 0.153 nits, which is impressive in itself.
How about color? I measured the primary and secondary color coordinates and plotted them against a known standard — the ITU BT-709 color gamut, which is the basis for HDTV production and transmission. The resulting coordinates were so close after my first pass that I went into the service menu to see if I couldn't make them line up exactly by playing with luminance and hue values.
The result? I was able to get the red, green, blue, yellow, and magenta coordinates to hit the BT-709 coordinates right on the nose. Only the cyan coordinate was a bit off, shifting more towards green than blue, and that might have required changes in the phosphor formulation.
This high accuracy in color was another change from the PRO-FHD1, which had a noticeable shift towards cyan in its green channel and could not cover the BT-709 gamut precisely. Note also that none of these improvements came at the expense of brightness, except when viewing the images at high or low vertical angles.