In a previous article i have mentioned the difference between cool and warm white – essentially the relative proportion of red and blue light in the white light beam. There is more to it than just that, and i suggest you have a look at the blog about colour rendition.
Some light sources provide an “empty” feel, with a starkness that feels uncomfortable. Typically this is due to a low Colour Rendition Index or CRI. Street lighting is a good way of illustrating this point, particularly the orange “sodium” lighting – much of which is being replaced by LED. Imagine you are out walking the dog before retiring for the night. You walk past a number of cars parked in the street, and if you stop to ask the question “is that a grey or a blue car” you may not be absolutely sure!
Of course this doesn’t matter when you are out there walking the dog. You have enough light (hopefully) to feel safe and to avoid objects on the footpath, so the lighting is appropriate, but you wouldn’t be happy with that quality of light indoors when you are just wanting to chill!
Another factor in creating pleasing ambiance is to be aware of and avoid glare. Very simply that is the main motivation for lamp shades… Bare globes are ugly and … well too bright! So we hide them behind a shade.
Recent developments in lighting (LED down-lights) are a case in point. Cheap to manufacture and hence cheap (and nasty?) at the point of sale, they are becoming the electrical contractors preferred option for lighting up domestic and commercial spaces. But they are (and there is no way of saying this nicely) quite horrible! The fact that they have a wide coverage – sometimes thought to be an advantage – is actually the issue when it comes to creating a comfortable ambiance. Not very clever! You don’t need to see the source of the light to feel comfortable. You are driving your car at night. You see a rabbit on the road. You are quite comfortable (if a little troubled about hitting the rabbit) but the rabbit is startled by your car’s headlights and likely as not, will freeze… with an almost predicable “bad” ending to the story.
So at home when you are thinking about lighting design for a new home, or trying to understand why your lighting does not work well, this might be the key. Are you in the driver’s seat comfortable and seeing your immediate environment well lit, or are you that hapless bunny, wondering what to do, and where to run to take cover.
In commercial spaces glare can be counter productive to creating a comfortable space allowing for relaxed dining or considered retail therapy.
I was transiting through my local airport one evening recently. It has been the subject of a recent upgrade with the replacement of florescent tubes with very glarey LED downlights on a very high ceiling. It has created a very harsh space, where everybody finds themselves grabbing their bags of the caraselle and rushing for the door. The coffee vendors where already closed. There was no point them being open, nobody was going to buy a coffee even while they waited for a taxi. It could have been done rather better if the specifiers had understood a bit more about glare.