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Optics in outdoor lighting

  • Optics in outdoor lighting
Sep 20, 2021

Why using the right optics is essential in outdoor lighting

Correctly lit roads are safer roads with fewer accidents.  Lit areas are more accessible at night and deter crime.  Lighting our highways with care helps all users, be it driving in bad weather, driving at night, walking your dog, or jogging alone. 

Performance at the heart of design

Lighting designers need good optics to perform the aesthetic and functional demands of transforming the spaces we enjoy and frequent.  For every road project, optics must therefore be fit-for-purpose and accommodate the expectations of contractors, end-users, and local authorities.  Lighting schemes rejuvenate our towns and cities and give ordinary places character.  At Thorn, our luminaires use only the most appropriately engineered optics for your chosen road application.

The modernisation of public spaces means more users can benefit from good light. Open spaces become safer and more accessible whilst respecting the nocturnal ecosystem. Lighting designers can achieve all this using our optics while protecting nature and conserving energy to safely light our streets.

Reduced glare

A successful road lighting installation must consider cost, energy consumption, light pollution, and importantly glare.  Glare can be caused directly by luminaires themselves or be reflected from surfaces. In road applications glare mitigation is especially pertinent for safety to prevent any impairment of driver vision.  For pedestrians comfort optics must be able to limit maximum luminance and vertical illuminance. Thorn has developed a range of R-PEC optics to control luminaire glare and limit scattered light for the purpose of lighting your highways and communities.

Thorn’s high-performance light engine can be used in our robust street lantern Isaro Pro and features the best in class optical performance.  Our optics offer several precision light distributions, achieving wide column spacing, and excellent uniformity, along with no spill or obtrusive light, whilst delivering high efficacies.  Uniformity, balanced brightness, and reduced glare are particularly vital to motorway lighting ensuring drivers arrive safely at their destinations.  Isaro Pro delivers high performance and reliable control with UrbaSens intelligent technology. 


With so many options of light distribution, precise light placement will transform open spaces, roads and more. Precise optical control prevents scattered light disrupting the night skies and stops light unnecessarily invading homes. Thorn’s R-PEC quality luminaires managed with intelligent controls reduce energy consumption and overall operating costs.Our range of optics, tilt capability, tuneable flux and programmable drivers facilitate optimisation of lighting design and minimise power consumption.  In urban streets our Thor lantern can provide high user comfort along with easy integration of connectivity and sensors for a wide choice of control options.  In a residential setting with even more varied users light must be carefully balanced.  A post top LED lantern like Plurio eliminates light spill and gives a lifetime of low-cost ownership (100,000 hours).

Road application flexibility

Our optics are adaptable for any road scenario:

  • Extra-narrow road recommended for P & M classes
  • Narrow road optic recommended for P classes
  • Wide road optic recommended for M classes
  • Extra-wide road optic recommended for C & M classes
  • Road comfort optic recommended for P classes
  • Road wet optic recommended for P classes
  • Wide pathway optic recommended for comfort P classes


The Raze product family incorporate Thorn’s innovative, patented Flatbeam technology, which transforms the way we light paths and façades. A high utilisation factor ensures light is directed onto the desired surface to be lit, and nowhere else. The flat and wide (4m) light distribution makes it possible to reduce the volume of products installed whilst maintaining continuous illumination. A comfort variant with internal louvre is available (Wide Path Comfort).  Equipped with motion detection sensors, DALI or LRT will provide optimum night-time control.  Raze allows designers to go the extra mile and achieve the perfect effect.  This technology also encourages the use of fewer precious materials and saves energy.

Why are our products so reliable?

Our sophisticated optics not only bring reliability but also reduce light emissions especially in street lighting. We have honed our product range to direct light where it is really needed with an extensive range of optics. LEDs used in our fixtures are tested and verified to last as promised for life of the 5-year warranty. The chromaticity stability is reliable, and we work with the best suppliers to ensure colour uniformity. The white LEDs used for our luminaires are selected based on chromaticity, lumen output, and forward voltage.

Safety First

Our optics are vital for areas such as cycle paths to significantly cut the number of accidents from early to late evening. To avoid collisions, cyclists must be able to make out other road users, pedestrians, and obstacles from a safe distance. Within built-up areas, cycle path lighting is often provided by general street lighting. However, using Flatbeam, a suitably wide-angled light distribution can prevent the creation of dark areas. Cycle paths away from roads, in parks or gardens need a dedicated lighting solution tailored to cyclists’ requirements. It should facilitate orientation, mark paths, and reveal the condition of the path surface. When choosing luminaires, care needs to be taken to ensure appropriate mounting heights, light colour, and optical control.  Our Urba range is ideally suited to the needs of cycle paths because it offers 25 light distributions and five mounting options.

The bigger picture - trusted performance

Lighting designers selecting products are ever mindful of green building practices. Ensuring sufficient environmental protection is easy with the right Thorn luminaires.  Each design decision can impact the environment, for example choosing colour temperatures that are less attractive to nocturnal insects and animals. Sustainable future proofing is no problem as upgrades of the optic and controls can be performed easily on site when needed.  Thorn’s precise optical controls for all outdoor areas protect dark skies and smart controls reduce energy consumption and see faster returns on investment.

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