LG Electronics 42LP1D LCD HDTV and 42PX4D Plasma HDTV HT Labs Measures: 42LP1D

HT Labs Measures: LG 42LP1D LCD HDTV

Full-On/Full-Off Contrast Ratio—966:1; ANSI Contrast Ratio—473:1

Measured Resolution with the Leader LT-446: 480: 480 (per picture height) 720p/1080i: out to the limits of the 1366 by 768 panel

DC Restoration (poor, average, good, excellent): Average (poor in daylight mode)

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

Measured Color Points:
Red Color Point: x = 0.636, y = 0.342
Green Color Point: x = 0.284, y = 0.603
Blue Color Point: x = 0.147, y = 0.074

The left chart shows the 42LP1D'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 warm color-temperature mode and the nighttime picture mode, measures very cool with dark images and gets somewhat warmer with brighter images. After making adjustments using the Photo Research PR-650, the gray scale measures within 670 Kelvin of D6500, the accurate color temperature, across the entire range (though mid-tones start drifting cool).

The right chart shows the gray scale (or color temperature) relative to the color points of the display's red, green, and blue color filters. These are fairly close to those specified by SMPTE. Green is slightly blue-green. Red is slightly reddish-orange. Blue is pretty much accurate.

Using a full-field 100-IRE white (142 foot-lamberts) and a full-field 0-IRE black (0.147 ft-L), the contrast ratio was 966:1. Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 473:1.—GM