Projector Reviews

Full-On/Full-Off Contrast Ratio: 23,725:1

For the picture adjustment settings used in this review, go to HomeTheater.com. Except as noted, all of the measurements here were taken with the projector adjusted for optimal home theater viewing in my room, exactly how I watched it during the review period. The black clip point was correct at digital 16, and the white clip point was just over digital 240, providing headroom above the white threshold at digital 235. The lamp was on High, Lens Aperture at –5. The contrast measurements were performed with the gray scale tightly adhered to the D65 target across the brightness range, a custom gamma curve averaging 2.26, and a very accurate Rec. 709 color gamut. There were 40 to 50 hours on the lamp for the Before Calibration measurements and 130 to 140 hours for the contrast and After Calibration gray scale and color gamut measurements. Contrast was measured with a Minolta T-10 meter aimed at the projector lens. (The top-end light output referenced in the review was measured off the screen with a Minolta LS-100.) Color, color tracking (gray scale), and gamma were measured off the screen with a Photo Research PR-650. The screen was a Stewart Filmscreen StudioTek 130 G3, 92 inches wide, with a gain of 1.3.

The full-on/full-off contrast ratio is very real world and was taken with the DLA-X7 set up exactly how I watched it, including the same lens throw (zoom). That’s an excellent result. However, leaving the lamp on High but maxing out the zoom and closing the iris all the way down to –15 resulted in a measured 52,500:1 contrast. That’s respectably close to JVC’s specified 70,000:1 contrast, especially considering that the lamp had over 130 hours on it, it was calibrated for D65 across the brightness range, and set up for home theater viewing. If I’d torqued up the brightness and contrast beyond accurate values, it might have hit or exceeded its spec, which is very rare.

The Before Calibration color tracking result is for THX Mode. I used the Custom Gamma settings to dial in the gamma curve and the color tracking/gray scale at many points across the brightness range. It was tedious, but the results are spectacular. Our color-tracking chart shows tight overlap of the three primary colors, indicating close adherence to the D65 standard across the range. The Delta E values were well under 1 from 20 IRE to 90 IRE, and only 2.5 at 100 IRE, which means the deviation from the standard is far below the visible threshold across the entire range.

The CIE chart shows that the color management system workaround of reining in a wider gamut to the Rec. 709 HD standard worked to perfection. Deviations in saturation, hue, and luminance were under the 3 Delta E visible threshold for all six primary and secondary colors. That’s as good as it gets.—SCB