The luminaires should not be mounted less than 25° or more than 45° above the centre of the pitch.
This is one of the general principles that will ensure that illuminance conditions comply with UEFA’s guidelines.
If possible, luminaires should be mounted at least 20–25m above the pitch surface. If this is not possible, it is important to develop a design solution that considers the implications of that reduced height and any implications for player discomfort glare.
One way to ensure that players’ discomfort glare is kept below RG 50 (see Discomfort glare) is to limit the floodlight’s angle of tilt to 70° for HID luminaires and 60° for flat panel LED luminaires as indicated in the diagram in Luminaires focus point angle section. However, the structural design of some stadiums may make this impossible. The level of discomfort glare should be evaluated during the design process and records maintained for reference.
The use of luminaires with asymmetric light distribution may be used along the pitch sides in order to produce good illuminance levels and uniformity along the adjacent pitch perimeter. In this way, asymmetric luminaires often help to reduce the levels of glare experienced by players and officials.