ViewSonic LightStream Pro7827HD 3D DLP Projector Review Test Bench

Test Bench

Full-On/Full-Off Contrast Ratio: 808.75:1



Pre-calibration measurements were made in the Rec. 709 preset at the default settings. Post-calibration measurements were made in the ISF Night mode. Maximum contrast measurements were made with the Normal lamp mode active. In this setting, the ViewSonic’s black level measured a so-so 0.048 ft-L, but peak white was a bright 38.82 ft-L, resulting in a contrast ratio of 808.75:1.

Highest peak brightness was delivered by the default settings in the Dynamic mode: 47.44 ft-L. Fan noise in this and other modes with Lamp Power set to Normal or Dynamic was notably loud.

Before calibration, the ViewSonic’s Normal color temperature preset in Rec. 709 color mode delivered a reasonably accurate grayscale with even tracking. The Delta E of its pre-cal grayscale averaged out to 6.4. Calibration knocked that figure down to 2.4, with a high of 8.8 at 20% brightness. (Delta E is a figure of merit that indicates how closely a display adheres to the Rec. 709 HD color standard. Experts generally agree that levels below 3 are visibly indistinguishable from perfect color tracking.)

The Delta E of the ViewSonic’s color points in the Rec. 709 mode’s default settings averaged out to 10. Calibration using the projector’s color management system resulted in a slightly improved Delta E of 6.

With the 3 Gamma preset selected, gamma in the Rec. 709 mode averaged 2.1 and displayed even tracking. Post-calibration, gamma remained linear and averaged 2.2.

Picture uniformity was excellent. The ViewSonic passed most of our high-def video processing tests, with the exception of 2:2 pulldown. Clipping was also an issue, with the projector showing no detail in the RGB channels of the Clipping test pattern from the Spears & Munsil Blu-ray test disc.—AG