Light pollution is “the alteration of the natural quantity of light in the night environment due to the introduction of artificial light”. Artificial light pollutes when it alters the amount of natural light present.
Except to turn lights off, instead, we are going to analyse the correct behaviour to adopt to avoid light spill. Let's find the right balance between light and dark while using light to enhance architecture responsibly.
On a practical note, in gardens we recommend directing the luminous flux very precisely to ensure it remains within the surface to be lit, and avoid it spreading beyond.
Sometimes it is enough to choose a tiltable recessed fixture over one with fixed optics, or a projector over a recessed fixture.
Sometimes the use of grazing light along the walls or the ground helps to reduce dispersion.
At other times, however, these measures are not enough, and you must take into account the performance of the fixture itself, as in the case of garden bollards.
A bollard’s reliability resides, above all, in the quality of its optics, which direct the luminous flux where needed, minimising or even eliminating upward dispersion and uncontrolled reflections.
A high-power recessed fixture installed in the lawn and pointing directly at the sky ... can definitely be put to better use elsewhere 😀