Since the light source provided by the LCD display has a certain directivity after being refracted and reflected, the color distortion phenomenon will occur when viewing beyond this range, and the CRT display will not have this problem.
The viewing angle determines the size of the user's viewing range and the best viewing angle. If it is too small, the user deviates slightly from the front of the screen, and the picture will be discolored. The general user can use the 120-degree viewing angle as the selection criterion.
The viewing angles of LCD monitors sold on the market are bilaterally symmetrical, but the upper and lower sides are not necessarily symmetrical, and the upper and lower angles are often smaller than the left and right angles. When we say that the viewing angle is 80 degrees to the left and right, it means that the screen image can still be clearly seen when standing at a position starting at 80 degrees from the normal of the screen (the imaginary line in the middle of the display). The larger the viewing angle, the better the viewing angle, and the more suitable the LCD display.
Since each person's vision is different, we take the contrast as the standard. The greater the contrast measured at the maximum viewing angle, the better. Most products on the market have a viewing angle of more than 120 degrees, and some products have reached more than 170 degrees. It should be noted that under different measurement methods, the nominal value of the viewing angle is also different. Since display manufacturers usually do not specify a specific measurement method, in general, the viewing angle is a reference value.