Viewing Angle of TVs

Our viewing angle video demonstrates the comparative quality of a TV’s viewing angles played at different angles. If you want to get an idea of what a TV looks like at wide viewing angles, this video should help. Below are four examples with different panel types and technologies: an IPS TV (Sony X800H), VA panel (Hisense H9G), VA panel with viewing angle technology (Samsung Q80/Q80T QLED), and an OLED (LG BX).

Color washout is when colors start to lose their chroma, or when they lose their saturation. If you're looking at a standard blue color, it loses its chroma when it starts to look blue/gray and no longer the same color. To test for color washout, we measure pure red, blue, and green, and we measure the angle at which each color drops to 80% of its original chroma. These graphs aren't very difficult to read; the x-axis represents the viewing angles and the y-axis represents the color's chroma. The horizontal line represents 80% of the original chroma and colors lose their chroma when they drop below that line.

For the rest of the article, we're going to compare the Sony X800H (IPS) and the Hisense H9G (VA) and their individual results. The differences are more noticeable than if we compare them with a VA panel that has viewing angle technology or an OLED. As you can see below, colors start to washout a lot quicker on the Hisense than the Sony.

Color washout - Sony X800H

Color washout - Hisense H9G

For the color shift, we use the same measurements as the color washout but instead look at the hue, which defines how close a color is to one of the six main colors: red, orange, yellow, green, blue, and purple. A hue shift happens when a color starts to appear either more red or more blue, depending on which end of the color spectrum it's moving towards. Hue is measured in degrees, and a three-degree change is considered a color shift.

The graph is a bit different from color washout; there are two horizontal lines that represent the three-degree color shift. The color changes hue when it passes these lines. As seen below, colors quickly lose their hue on the Hisense, but they remain the same even at very wide angles on the Sony.

Color shift - Sony X800H

Color shift - Hisense H9G

Contrary to what the name suggests, we don't actually measure if the TV loses brightness and becomes dim in this test, but rather how much lightness it loses. In other words, we want to know at which angle the image starts to appear darker. We measure the lightness using six test slides: pure black, 20% gray, 40% gray, 60% gray, 80% gray, and pure white, and we measure each slide at various angles. The pure white slide has a lightness measure of 1.0, while pure black is 0.0, and we want to see when the lightness of any of the slides drops to 75% of its original value.

As you can see, the image retains its brightness at wider angles on the Sony than the Hisense. Pure black actually becomes lighter on the Hisense at very wide angles, meaning it's not pure black anymore.

Brightness loss - Sony X800H

Brightness loss - Hisense H9G

Black level defines how bright the screen is when displaying the pure black slide from the brightness loss test. An OLED has a black level of 0 because each pixel is individually turned off, and an LED TV with a VA panel has a very low black level because it's not emitting much light. However, a high black level means that blacks look gray because there's still light emitting out, and this is typical of IPS panels. The black level raise measures when the black level doubles its lightness, causing blacks to appear gray. Between the Sony and Hisense, the Sony's black level doesn't change much even at 70 degrees, while the black level on the Hisense doubles at 20 degrees off-center.

Gamma defines the brightness of shades of gray. Having a TV with a proper gamma is important for scenes or games with shadows. A high gamma causes the image to appear too dark, while a low gamma results in a bright image. Using the same grayscale slides from the brightness loss test, we want to see at which angle the grays start to change. Looking at the graphs above in brightness loss, you'll notice there are dotted lines, and these represent the ideal gray value relative to pure white and pure black. If the grays start to deviate from the dotted lines, it means the gamma is shifting. As you can see, the Sony maintains gamma stable for wide viewing angles, while the Hisense starts to shift at narrow viewing angles and 20% gray starts to look like 40% gray.