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10 best practices for minimising obtrusive light

Jun 04, 2020

Be on where it counts

Top sports performance requires athletes to be on their game when and where it counts. The same is true of top sports lighting performance. Optimally illuminating sports facilities, both professional and recreational, calls for smart solutions that deliver superb lighting quality while keeping negative effects to a minimum.

Thorn is committed to providing the right light for people, places and the environment – as it has for numerous indoor and outdoor sports facilities of every scale. The following 10 points provide guidance for reducing problematic light effects when planning a sports lighting project.

10 best practices for minimising obtrusive light

1. What is obtrusive light?

The term obtrusive light refers to various harmful effects that lighting can have for the surrounding areas of sports sites and for the environment. It is important to be mindful of the following:

Sky glow – brightening of the night sky

Spill light – light falling into surrounding areas

Intrusive light – light that disturbs occupants in surrounding areas; also referred to as light trespass

Additional considerations should include:

Glare – uncomfortably bright light

Flicker – rapid light pulse fluctuations

2. What general lighting standards apply?

EN 12193, the European norm for indoor and outdoor sports lighting, defines permissible limits for obtrusive light such as spill light and glare. It distinguishes between three levels of competition: professional, regional/local and training/recreational. Other requirements are defined by sports governing bodies such as the FIFA as well as local authorities. The document most recommendations are based upon is CIE 150. Thorn experts are well-versed with all types of lighting standards and can provide support.

3. How is sky glow calculated?

Today, floodlights are commonplace even at smaller outdoor sports facilities. With these as with large installations, care must be taken to minimise brightening of the night sky and disruption to the surrounding ecosystem. The upward light ratio or ULR plays a crucial role here. It is used to measure the proportion of light that is emitted by a luminaire at or above the horizontal when mounted. No-tilt solutions like the Champion LED floodlight from Thorn emit virtually no upward light, making it an ideal fit for small stadiums and training grounds wanting to keep artificial sky glow to a minimum.

4. What effectively controls spill light?

Light spill and trespass can be disruptive to residential areas, infrastructures and people located in the immediate vicinity of sports venues. Curtailing it is best achieved with lighting technologies equipped with precise optics that direct the light only to where it is needed. Case in point: The modular and powerful LED floodlight Altis from Thorn. Offering highly flexible configuration options for a wide spectrum of applications, it focusses the light with a tightly defined cut-off to very effectively minimise spill light.

5. What about glare?

The uncomfortable “halo effect” frequently associated with glare can negatively impact the performance of athletes and hamper the visibility of spectators. The CIE 112 evaluation system developed by the International Commission on Illumination provides guidelines and a rating scale for assessing the glare levels of outdoor sports lighting installations. An LED floodlight like the Areaflood Pro from Thorn scores well on the scale. Featuring a lumen package optimised for three sizes, superb optics and lighting controls, it maximises illumination levels while simultaneously reducing glare.

6. Is flicker an issue?

Flicker, the rapid series of light pulses typical of all artificial lighting, can also have detrimental effects for humans and other species. What’s more, it can be problematic for HD or 4K TV transmissions in stadiums and arenas, particularly for capturing super slow-motion images. A flicker factor under 6%, less than 1% with LEDs, is highly recommended. Flicker-free LED lighting solutions from Thorn ensure brilliant colour rendering and uniform light distribution with minimal negative effects.

7. How can control solutions help?

Most facilities are used for various sports and other activities, each requiring different lighting levels and scenarios. Smart lighting control solutions enable quick and convenient light level adjustment and balancing. They can be preprogramed to shut off lighting when not in use, thereby significantly helping to minimise excessive brightness at night while also saving energy and maintenance costs. Thorn offers a range of highly effective lighting control packages for professional as well as recreational indoor and outdoor sports facilities.

8. What about luminaire design features?

Luminaires with highly efficient shielding and reflector designs enable further spill light and glare control by largely containing the light within or redirecting it back onto the playing surface. Champion LED from Thorn can be equipped with an anthracite painted visor or a high-reflectivity material visor, each offering excellent spill light control. When intelligent design is combined with intelligent control, lighting installations with fewer luminaires and lighting columns are often possible.

9. What advantages does LED lighting offer?

LED luminaires can easily be dimmed, or turned off, as needed. Also, they are generally designed to very specifically focus the light beam. In this way, they help to prevent the light from scattering into areas adjacent of the sports site. Design features of LED floodlights from Thorn provide additional safeguards against light pollution. The high-powered Altis floodlight, for example, greatly reduces obtrusive light by asymmetrically focussing the light forward at 0° tilt.

10. How important is proper planning?

The proliferation of sports lighting systems even at smaller venues in recent years has led to an increase in night sky brightness around the world. It has also prompted an increased awareness for the need to carefully design and plan a new lighting installation or retrofit, especially given the broad diversity of sports sites. Thorn experts are very skilled and knowledgeable at designing and implementing sports lighting systems that provide optimal performance with minimal pollution. They can offer assistance at every step of a sports lighting project, also as a turnkey solution.

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