Polk Audio RM40T Speaker System, Hitachi 42HDT52 Plasma HDTV, Yamaha RX-4600 A/V Receiver, and Yamaha DVD-S2500 DVD Player HT Labs Measures: Hitachi

HT Labs Measures: Hitachi 42HDT52 Plasma HDTV



Full-On/Full-Off Contrast Ratio—447:1; ANSI Contrast Ratio—360:1

Measured Resolution with the Leader LT-446:
480: 480 (per picture height)
720p: 720 (pph)
1080i: 850 (pph)

DC Restoration (poor, average, good, excellent): Good

Color Decoder (poor, average, good, excellent): Good

Measured Color Points:
Red Color Point: x=0.646, y=0.339
Green Color Point: x=0.235, y=0.684
Blue Color Point: x=0.150, y=0.063

The left chart shows the 42HDT52's gray scale relative to its color temperature at various levels of intensity, or brightness (20 IRE is dark gray; 100 IRE is bright white). The gray scale as set by the factory, in the standard color-temperature mode, measures warm with dark images, a little cool with mid-tones, and back to a little warm with brighter images. After making adjustments using the Photo Research PR-650, the gray scale measures within 348 Kelvin of D6500, the accurate color temperature, across most of the entire range. The darkest images are still warm.

The right chart shows the gray scale (or color temperature) relative to the color points of the display's red, green, and blue phosphors. These are somewhat off to those specified by SMPTE. Red is slightly over saturated and slightly reddish orange. Blue is very slightly greenish blue. Green is over saturated and somewhat bluish green.

After calibration, and using a full-field 100-IRE white (19.22 foot-lamberts) and a full-field 0-IRE black (0.043 ft-L), the contrast ratio was 447:1. Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 360:1. With a 100-IRE window the 42HDT52 produced 72.96 ft-L. (it is normal for a plasma to have lower light output on a full field white versus a white window).—GM