This is how CHIP tests televisions
In our complex TV measurement process, we use the LMK98-3 luminance and chromaticity meter to check the televisions in our test lab. The most important rating is the picture quality, which accounts for 60 percent of the final grade. We record the maximum brightness of the television, the intensity of a 4 x 4 checkerboard 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 adheres to the specifications of the gamma value reference curve 2.2 in the display of the relative brightness/contrast curve. If there are deviations here, there can be a loss of detail in areas that are too dark or too bright. We measure how accurately the white representation adheres to the so-called D65 reference at a color temperature of 6500 Kelvin and how evenly the illumination of completely white and almost black areas is. Sometimes visible clouds of light (clouding) or stripes (banding) appear here, which we devalue. We also record and evaluate from which viewing angle (horizontal and vertical) the contrast is halved. This tells you how stable a device keeps 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 moving image display in different resolutions for the display of partly progressive and partly interlaced image material.
According to the image quality, we measure the Furnishing the second highest weight. It accounts for 25 percent of the overall 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 (e.g. HEVC, HDR, DTS) as the range of functions and usability of the smart TV system, if available. The quality of the remote control is included in the equipment as well as any voice control. There are additional 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 this is a great feature that enhances the fun of watching movies and TV.
the energy efficiency contributes 10 percent to the overall rating. In the past we have evaluated the power consumption in “Movie” mode (or a comparable profile) in a standard sequence in SDR quality – without changing the preset brightness. However, television sets vary in brightness here. One model may 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 likes, we changed the measurement in our television test. We are currently setting all new TV sets for the SDR power consumption measurement in such a way that they display a 10 percent white field with around 250 cd/m² brightly – this makes it easier to compare the efficiency of the devices. The calculation formula takes the image area into account. A very large TV can, in our opinion, be just as efficient as a very small one, although it consumes more. Additionally, 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 switch their brightness to maximum here.
sound quality, which we weight at 5 percent, is a purely subjective grade. We differentiate here between the reproduction of male and female voices and note how loud and full the TV sounds and whether tonal artifacts such as clinking and rattling occur. Ultimately, however, it should be noted that even a cheap soundbar sounds better than many televisions. Only TVs with an integrated soundbar can keep up.