Sharp LC-90LE745U 3D LCD HDTV HT Labs Measures
Full-On/Full-Off Contrast Ratio: 6,720:1
All the post-calibration measurements shown here, and all the observations in the review itself unless noted otherwise, were performed in the Movie AV Mode for 2D and 3D, through an HDMI input with the set adjusted as needed for the most accurate image in a darkened room.
The Sharp’s black level increased or decreased depending on the presence of small areas of brightness on an otherwise black screen. I selected 0.002 foot-lamberts—the measured black level with the pause bug of a Blu-ray player at the lower left of an otherwise fully black screen, as most likely representative of the set’s black level in dim, low-contrast scenes. The 2D contrast ratio above was calculated from this 0.002-ft-L reading and a measured peak white level of 13.44 ft-L. The Contrast setting was +29, the Brightness setting was +1, the Backlight at –12, and the Gamma Adjustment at –1.
The Before Calibration RGB Balance, shown in the charts with the Color Temperature at Warm2, was not inspiring. The white balance Delta E values ranged from a low of 5.57 at 20 percent brightness to 19.02 at 100 percent, with an average value of 10.85. Post calibration, using the two-level calibration controls, this improved to a low of 0.6 at 20 percent to 3.78 at 100 percent, with no values higher than 2.78 from 20 percent to 90 percent and an average value of 1.76.
Delta E is a figure of merit that indicates how closely a display adheres to the HD color standard. Experts generally agree that levels below 3 to 4 indicate a result that’s visibly indistinguishable from perfect color tracking. Delta Es can be used to characterize either white balance (gray scale), as above, or color, as below.
The Sharp’s After Calibration 2D color gamut was reasonably close to the Rec. 709 HD standard. Only the red controls lacked sufficient range to bring that color into line. Nevertheless, the red Delta E, the worst of all the post-calibration colors, was a good 3.21, with an overall Delta E of all the colors an excellent 1.48 (down from 4.85, pre-calibration).
The set’s 2D gamma, in its –1 setting, averaged 2.31—a high of 2.34 at 40 to 50 percent brightness and a low of 2.29 at 80 percent.
For 3D (charts not shown), the post-calibration 3D gray scale Delta E averaged 1.68, the overall color Delta E 1.12, and the gamma (at a setting of 0) 1.97.—TJN