What’s in a lux?

BLOG

Singapore, 24^rd April 2014

One of the most frustrating discussions is when clients ask you for lux calculations…at least when it comes to clarifying a lighting design for mood or ambience…As it happens I received coincidentally a request from two different clients today asking us to carry out lighting calculations to check out the lux levels because looking at our plans they felt that the lighting layout was not covering the space adequately and they were worried to have “dark spots”. OK fair enough, if you do not fully understand the nature of light you may be worried that there is not enough light when you don’t see a lighting point. The thing is that light is a 3 dimensional thing that interact with the architectural space and the material finishes in it.

I try to explain to my client as follows; in a square room I can have one central pendant or ceiling light that will light up the space. It will have the light concentrated in the middle of the room with little focus on what is happening on the walls. Alternatively I can have one down/wash light on each of the 4 walls; the result being that the architectural space is well defined, the materials are well illuminated, the overall appreciation of the room very pleasant. However we may well find that the (average) lighting levels are much lower than with the central ceiling light option. In my case the client had circled the centre of the room asking whether the centre was too dark and whether I could carry out a lux calculation to show him there was enough light!

We don’t design for lux meters I keep saying time and again. A white surface with 100 lux looks brighter than a black surface with 100 lux, yet both have the same lighting level…will the lux calculation really help to get a proper feel of the lighting in that room? Unless you are an expert lighting specialist as we are who know how to interpret lux calculations, we should keep our clients as far away as possible from it….

Light Watch 5-67: As I was looking for illustrations for this subject I stumbled on to the work of Nonotak Studio’s (www.nonotak.com), a collaboration between an illustrator and an architect musician. Their work was created out of a commission to develop a mural in a public housing building in Paris…it just illustrates that lighting and defining a space is not always about lux levels…light is emotion!