How to test CHIP television
In our complex TV measurement process, we use the LMK98-3 luminance and chromaticity meter to check the televisions in our test laboratory. The most important assessment is image quality, which makes up 60 percent of the final grade. We record the maximum brightness of the television, the intensity of a 4 x 4 shaft grid contrast (consisting of white and black fields), the maximum color space size that can be displayed, and the so-called gamma curve.
The latter shows how precisely a TV complies with the specifications of the gamma value reference curve 2.2 in the display of the relative brightness / contrast curve. If there are deviations here, then there may be a loss of detail in areas that are too dark or too light. We measure how accurately the white representation complies with the so-called D65 reference at a color temperature of 6500 Kelvin, and how even the illumination of completely white and almost black areas is. Sometimes visible clouds of light (clouds) or streaks (bands) appear here, which we devalue. We also register and evaluate from which point of view (horizontally and vertically) the contrast is halved. This tells you how stable a device maintains the image quality at different viewing angles.
The measurements are followed by subjective tests, which, among other things, look at the detail display in very dark scenes, in bright highlights and the like – in HDR and SDR. We also classify the display of live images in different resolutions for the display of partly progressive and partly interlaced image material.
According to the image quality, we measure interior design the second highest weight. It accounts for 25 percent of the total result. We evaluate the number of inputs and outputs such as HDMI, USB, cinch, jack, network and the available tuners. The format support is just as relevant in this category (eg HEVC, HDR, DTS) as the range of features and usability of the smart TV system, if available. The quality of the remote control is built into the equipment as well as any voice control. There are extra points for a light sensor and for Ambilight. The latter is a Philips technology: LED strips, which are located on the back of the TV, illuminate the wall behind the TV to match the color of the picture content. We think it’s a great feature that makes watching movies and TV more fun.
that energy efficiency contributes 10 percent to the overall rating. Previously, we evaluated the power consumption in “Movie” mode (or a comparable profile) in a standard SDR quality sequence – without changing the preset brightness. However, TVs vary in brightness here, one model can work with 200 cd / m², another with over 500 cd / m².
Since the user is ultimately free to adjust the brightness as he or she wants, we changed the measurement in our TV test. We are currently setting up all new TVs for the SDR power consumption measurement in such a way that they show a 10 percent white field with about 250 cd / m² clearly – this makes it easier to compare the efficiency of the devices. The calculation formula takes into account the image area. A very large TV can, in our opinion, be as efficient as a very small one, even if it consumes more. In addition, we introduced an HDR power consumption measurement, which we perform on the same clip in HDR mode. We do not make any changes to the default settings. As a rule, the TVs change their brightness to maximum here.
sound quality, which we weight to 5 percent, is a purely subjective character. We distinguish here between the reproduction of male and female voices and note how loud and full-bodied the TV sounds, and whether tonal artifacts such as the clink and rattle occur. In the end, though, one can say that even a cheap soundbar sounds better than many televisions. Only TVs with integrated soundbar can keep up.