Hitachi 32HDL51 LCD HDTV HT Labs Measures: Hitachi 32HDL51 LCD HDTV
Full-On/Full-Off Contrast Ratio—535:1; ANSI Contrast Ratio—546:1
Measured Resolution with the Leader LT-446: 480: 480 (per picture height) 720p: out to the limits of the 1366 by 768 panel 1080i: out to the limits of the 1366 by 768 panel
DC Restoration (poor, average, good, excellent): Average
Color Decoder (poor, average, good, excellent): Average
Measured Color Points: Red Color Point: x=0.637, y=0.322 Green Color Point: x=0.290, y=0.602 Blue Color Point: x=0.143, y=0.082
The left chart shows the 32HDL51'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 and the night picture mode, measures slightly cool with dark and brighter images, though is fairly accurate in the middle. After making adjustments using the Photo Research PR-650, the gray scale measures slightly better, within 247 Kelvin of D6500, the accurate color temperature, across most of the range. The darkest of images were still 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 close to those specified by SMPTE. Green is slightly bluish-green, blue is slightly greenish-blue, and red is slightly purplish-red.
Using a full-field 100-IRE white (19.78 foot-lamberts) and a full-field 0-IRE black (0.037 ft-L), the contrast ratio was 535:1. Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 546:1. The best contrast ratio was achieved in the night setting and the back light set for 0%. The brightest image was achieved in the day setting with the back light set at 100%, which produced 87.5 ft-L with a 100-IRE window. The black enhancement feature creates a floating black level (i.e. it adjusts the black level depending on the picture). Using this feature the contrast ratio was significantly higher, though occasionally the black level adjustment was noticeable (visible) and therefore this feature is best left off for those seeking the most accurate picture.—GM