Horizontal and vertical viewing angle determine when colours and details remain entirely visible for the viewer. The bigger the angle, the more stable brightness and contrast stay with a sloping viewing perspective (left, right, top and bottom). The viewing angle maximum for the contrast is reached when the drop of the contrast ratio makes 1/5 of the initial value. It is important to have as large an angle horizontally and vertically as possible, so that the colours are displayed over the entire panel surface without any distortions. Modern SMD LED walls have a horizontal and a vertical viewing angle of 140°. Outside the viewing angle the colours tear off, the content of the display is often perceived as a bright (often pink) area.