Optoma H27 DLP Projector HT Labs Measures
Full-On/Full-Off Contrast Ratio—1757:1; ANSI Contrast Ratio—455:1
Measured Resolution with the Leader LT-446:
480: 480 (per picture height)
720p/1080i: out to the limits of the 852 by 480 DMD
DC Restoration (poor, average, good, excellent): Excellent
Color Decoder (poor, average, good, excellent): Good
Measured Color Points:
Red Color Point: x=0.653, y=0.339
Green Color Point: x=0.304, y=0.649
Blue Color Point: x=0.146, y=0.065
The left chart shows the H27'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 0 color-temperature mode and the Movie picture-preset mode, measures slightly warm across the gray-scale range. After making adjustments using the Photo Research PR-650, the gray scale measures better, within 177 degrees Kelvin of D6500, the accurate color temperature, across the entire range. This is slightly misleading, however, as dark images have an excess of green, and bright images have a lack of green. You can see this in the vertical trend in the color-temperature portion (center dots and lines) of the CIE diagram (right chart). Please refer to the text as to how noticeable this is.
The right chart shows the gray scale (or color temperature) relative to the color points of the display's red, green, and blue color-filter-wheel segments. Blue
is slightly oversaturated, red is slightly oversaturated and slightly reddish-orange. Green is oversaturated and slightly yellowish-green. These are somewhat close to those specified by SMPTE.
Using a full-field 100-IRE white (8.785 foot-lamberts) and a full-field 0-IRE black (0.005 ft-L), the contrast ratio was 1,757:1. Using a 16-box checkerboard pattern (ANSI contrast), the contrast ratio was 455:1. The best contrast ratio was achieved in the BriteMode-off setting. The brightest image was achieved, not surprisingly, in the BriteMode-on setting and produced 11.16 ft-L with a 100-IRE window and 0.007 on a 0-IRE black (on an 87-inch-wide, 1.0-gain Da-Lite Da-Mat screen). The contrast ratio in this mode was 1,594:1. Also, in this mode, the H27 tracks even closer to D6500, but it is our policy to use the measurements in the mode with the best contrast ratio.—GM