To maintain a standard across our review units, we calibrated the Samsung D7000 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 boosters such as color and dynamic lighting enhancement features.
Here are the recommended picture settings after a round of calibration - Brightness: 50, Contrast: 98, Color:56 and Tint:1. Black and white luminance values were given as 0.107cd/m2 and 227.778 cd/m2 respectively. The D7000 has an almost identical black luminance reading to the D8000, although the D8000's white luminance value was substantially higher at 356.656 cd/m2. With an average contrast ratio rating, let's see how the Series 7 fares in our visual tests.
DisplayMate is an application which generates a sequence of test patterns to determine the capabilities of imaging devices, like color and gray-scale accuracies for example. For our tests, we've hooked up the Samsung D7000 to our display test-bed PC using an HDMI connection. To be fair across the board, we have also disabled all visual enhancements on the TV in order to reduce the variables involved. Here are some findings based on the relevant and critical test patterns:-
Samsung's D7000 is plagued by uneven display issues similar to the D8000 model, such as brighter patches along the edges. Like most edge-lit LED sets, this discrepancy is less obvious on brighter backgrounds but becomes apparent with darker test patterns. This may also lead to a degradation of black levels around the panel's perimeter.
Dark Gray Scale
Slightly mismatched gray hues were noted on the test pattern. Deviations along the screen's edges and mid-portions of the panel were also evident as caused by the backlights' uneven uniformity.
Relatively accurate color reproductions for both primary and secondary colors. Viewing angles on the horizontal axis were commendable as well. However, gradients were visibly less linear on this model. For example, the darker blue band faded to black almost instantly, while the same applies to the rest of the remaining colors.
256-Intensity Level Color Ramp
Heavy and irregular compression was detected on the darker end of the spectrum. Similar to results derived from the Color Scales evaluation, gradients were far from ideal on the 256-Intensity Level Color Ramp test.
IDT's HQV Tests are designed to assess image quality 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 in order to stress the TV's video processor. This compels the TV's processor to convert interlaced signals into progressive to accommodate the HDTV's panel. Here are the results we noted on three crucial tests:-
Digital Noise Filtering
Samsung's D7000 is equipped with two noise filters - a Digital Noise Filter for weaker broadcast signals, and an MPEG Noise Filter to reduce MPEG noise. The latter didn't remove noise grains by much, although the digital filter was more effective when set to High. One caveat is the slight loss of picture detail in the process.
Diagonal Filter Test
Stable video de-interlacing, which improved by a notch after enabling the TV's LED Motion Plus and Motion Plus frame interpolation features. However, movement on the rotating bar appeared excessively smooth as a result, despite the jaggies-free performance.
Film Resolution Loss Test
Samsung has two cadence algorithms - Auto1 and Auto2. We found that the Auto1 selection worked best, since it identifies the source cadence before applying the appropriate inverse pulldown on the entire image. Auto2 should only be used when 3:2 pulldown has been applied to portions of the picture.