LCDs From Sony, Samsung, Toshiba & Philips HT Labs Measures: Sony

HT Labs Measures: Sony KDL-46XBR4 LCD HDTV

Full-On/Full-Off Contrast Ratio—17,143:1 (see below); ANSI Contrast Ratio—1,687:1

Measured Resolution with the Leader LT-446:
480: 480 (per picture height)
720p: 720 (pph)
1080i: 1,080 (pph)

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

Color Decoder (poor, average, good, excellent): Good (Wide), Average (Standard)

Measured Color Points:
Red Color Point: x=0.635, y=0.321
Green Color Point: x=0.252, y=0.635
Blue Color Point: x=0.148, y=0.064

The top chart shows the KDL-46XBR4'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 2 color-temperature mode and the Cinema picture mode, measures too far bluish-green off the black-body curve to get a color temperature with dark and bright images. The middle of the gray-scale range measures slightly cool. After making adjustments using the Photo Research PR-650, the low end of the gray scale is still exceedingly cool, and the upper mids are too warm.

The bottom 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 off those specified by SMPTE. Red is very slightly undersaturated and very slightly purplish-red. Green is oversaturated and bluish-green. Blue is very slightly greenish-blue. In the Standard color mode, green is more accurate, with x,y coordinates of 0.279, 0.614. This is still oversaturated and bluish-green, but less so. In this mode, red and blue essentially remain the same.

After calibration, and using a full-field 100-IRE white (120 foot-lamberts) and a full-field 0-IRE black (0.007 ft-L), the contrast ratio was 17,143:1. This number is 100-percent, totally false. Regardless of mode, the KDL-46XBR4 rides the video signal with its backlight, creating artificially high contrast-ratio measurements (much like an auto-iris on a projector). Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 1,687:1. Most LCDs have nearly identical ANSI and full-on/full-off contrast ratios, so this number is more accurate to the contrast ratio that this panel is actually creating. The "best" contrast ratio was achieved with the Power Saving mode set to Off and the backlight set to Max. This was also the brightest image. The best back level was achieved with the Power Saving mode set to High. The backlight setting did not affect the black level in this mode. Set like this, the KDL-46XBR4 produced 0.005 ft-L and between 22.49 ft-L and 47.29 ft-L depending on backlight settings (4,498:1 to 9,458:1—also false numbers).—GM