LCD TV Reviews

• Full-On/Full-Off Contrast Ratio—11,370:1; ANSI Contrast Ratio—1,753:1

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

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

• Color Decoder (poor, average, good, excellent): Excellent

• Measured Color Points:
Red Color Point: x=0.636, y=0.329
Green Color Point: x=0.270, y=0.583
Blue Color Point: x=0.145, y=0.065

The left chart shows the LT47X788'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 Low color-temperature mode and the Theater picture mode, measures extremely warm with darker images and only slightly warm with brighter images. After making adjustments using the Photo Research PR-650, the gray scale measures fairly close to D6500, the accurate color temperature, across most of the range. There is still a significant dip in the low end.

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 somewhat close to those specified by SMPTE. Red is very slightly undersaturated. Blue is very slightly oversaturated and very slightly greenish-blue. Green is slightly undersaturated and somewhat bluish-green.

After calibration, and using a full-field 100-IRE white (113.7 foot-lamberts) and a full-field 0-IRE black (0.010 ft-L), the contrast ratio was 11,370:1. This number is inflated, to say the least, due to the backlight tracking the level of the incoming video signal. This "feature" cannot be disabled. Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 1,753:1. These numbers were created with the Energy Saver mode set to +30. Decreasing this setting only decreases light output and does not affect black level. The Dynamic mode has about 20 percent more light output, but it disables certain settings in the user menu and as such was not used.—GM