To maintain a standard across our review units, we calibrated the Sony Bravia HX855 with Datacolor's Spyder3TV Home Theater Color Calibration kit prior to our visual tests. This is to ensure we assess the HDTV based on optimal display settings and not on visual estimation alone. Using the TV's Standard preset, we've also disabled all the necessary enhancement features.
Here are the recommended picture settings after calibration - Brightness: 12, Contrast: 98, Color: 51, and Tint: G1. Backlight levels are clamped at 6 throughout the calibration process. Black luminance was recorded at 0.020cd/m2, and white luminance at 84.159 cd/m2. That's a very healthy and deep black luminance reading, but we have to consider the HX855's rather weak white luminance levels as well. Such measurements normally indicate inky black levels but the TV might also suffer from 'black crush' tendencies as well. We'll have to work it out on DisplayMate to see how it really fares. Comparatively, full-array models like LG's LM9600 recorded 0.112 cd/m2 and 245.039 cd/m2 respectively, and Sony's HX925 at 0.310 cd/m2 and 281.755 cd/m2.
DisplayMate is an application which generates a sequence of test patterns to determine the capabilities of imaging devices, like color, uniformity, and gray-scale accuracies for example. For our tests, we've hooked up the Bravia HX855 to our display test-bed via a HDMI connection. Similar to our calibration setup, we have also disabled all visual enhancements on the TV to reduce the variables involved. Here are some of our findings.
|Screen Uniformity||The Bravia displayed excellent uniformity across all four colored backgrounds - white, red, blue, and green. A rare feat for an edge-lit LED display.|
|Dark Gray Scale||Even gray tones were observed. Sony's LED Dynamic Control (cluster dimming) feature may be required to improve overall black depths. Brightness levels have to be bumped up in order to reveal the darker gray blocks.|
|Color Scales||The OptiContrast panel handled the brighter hues with great accuracy. However, it had trouble rendering the darker gradients on the test pattern due to the TV's conservative luminance levels.|
|256-Intensity Level Color Ramp||Strong colors and smooth gradients were noted although it was less adept with the darker tones. This minor glitch may be an issue when viewing static photographic images.|
IDT's HQV Tests (on Blu-ray) are designed to assess image quality and handling of digital displays through a variety of video signal processing tasks which includes decoding, de-interlacing, motion correction, noise reduction, and film cadence detection. We've programmed the Blu-ray player to playback in 1080i to test the TV's de-interlacing capabilities. Here are the results we noted on some of the more crucial HQV tests:-
|Digital Noise Filtering||Like previous Bravias we've tested, the HX855's noise filters did not impress. Noise grains persisted despite pushing the Noise Reduction settings to High.|
|Diagonal Filter Test||The Bravia validated its de-interlacing muscle judging by the jaggies-free rotating bar displayed on the Diagonal Filter test pattern.|
|Film Resolution Loss Test||Impeccable cadence detection and processing were achieved on both Auto 1 and Auto 2 options under the TV's 24p (True Cinema) feature.|