John Bullock Lighting Design
John Bullock Lighting Design
Lighting Product DesignLighting Product Design
Heritage Lighting ProjectsHeritage Lighting Projects
Home Lighting ProjectsHome Lighting Projects
Exhibitions Lighting ProjectsExhibitions Lighting Projects
Leisure Lighting ProjectsLeisure Lighting Projects
Exterior Lighting ProjectsExterior Lighting Projects
Commercial Lighting ProjectsCommercial Lighting Projects

Lighting the Home: The Basics

25-11-2013

Let's look at the fundamentals of what we need to look for in our lighting:

It all comes down to: how much light / where is the light / what does the light say:
And these three things are seriously interwoven into our lives.

A note on the text:
There is general confusion about what a 'lamp' is.
In my world, a LAMP is a light source. It is not a FIXTURE - ever.


1. How much Light?

This is about having ENOUGH light to do things. Its difficult to create TOO MUCH light to be able to work (though reading while sitting in a deck-chair facing the sun is a pretty good example), but the situation of not having enough light happens every day . . . its why we switch on our lights in the first place.
Some tasks call for more light than others; the relationship between Sight and Light is not an absolute one -enough light to do a crossword puzzle doesn't mean you have enough light to thread a needle.
And this problem is often exacerbated by where the light is coming from.

2. Where is the Light?

Coming back to the deck-chair and the glary sun; that's a problem because you're looking at both the sun and the book at the same time; the book is in its own shadow and the sun is shining directly into your eyes. We usually get around this with a combination of sunglasses and sunshade - but the text on the page is still far darker than it could be.
If you were weird enough to turn your back to the sun, you'd find that the text on the page is far easier to read and you wouldn't need the sunglasses.

In most other ways, the relationship between light + task + us is a simple one. We know subconsciously to move around until we can see properly - the needle-threading experience again. Unless, of course, the task is in a fixed position (against a wall, perhaps); then we need to be a bit more creative.

3. What does the Light say?

Although this issue comes in at a low third in the priority stakes, it IS an issue and there are plenty of complaints about it.
This is about the way that Light influences what we see by changing the colour of a thing or an environment.
Light is not a fixed thing - it comes in lots of different tones of WHITE ('colour temperature' in the trade) and a bewildering variety of colour accuracy  ('colour rendering' as we know it)

Usually, the complaint comes as a mash-up of these three problems:
The light in my . . . is  horribly grey and its so poor that I can't see to . . . .

In all likelihood, its 'grey' because it's a 'cold' white colour (the cheapest range of LEDs will often display this unattractive feature), and people can't see because the light output is insufficient and the fittings are in the wrong place.
A perfect storm.

 

1. So how much Light do I need?

Everyone's eyesight is different, but we know that the older we get, the less effective our eyesight becomes. On top of that there's a whole range of eye problems that we can enjoy, from short-sight to macular degeneration - all bringing with them  their very own brand of fun.

Lighting within the home usually relates back to the 60W light bulb - the single-most popular light source ever - until it was banned on sustainability grounds.
(Filament lamps - even the 'ECO' branded ones are simply too costly in environmental terms to be considered part of our future. Which is a great pity.)

So strong is our relationship with the 60W light bulb that the new low-energy sources have been designed with 'equivalence' in mind. Without getting into numbers, the old 60W filament lamp produced 600lm (lm= the lumen, the unit of light output).
You should now find that all light sources have the light output rating on the box (and - for sure - if the lamp in your hand doesn't show it, put it back on the shelf and Walk Away) Lamps with an output of 600lm or above SHOULD provide a similar light output to our old 60W friend.
And that's what it says in all the text-books. My experience is that 600lm from one source doesn't always look the same as 600lm from another source, with the CFL (CFL = compact fluorescent lamp) being a particular culprit. I always go one (sometimes two) sizes up if I'm looking for a 60W-equivalent output.

The latest generation of LED light bulbs (the ones that look like light bulbs - not the ones that look like those tiny spotlamps) have improved enormously over the past year or so, and continue to do so. Light output from these is more effective, so expect to see a 60W-equivalence with LEDs sometime soon.

Referring this back to our question 'how much light', it becomes a personal question. Relative to an old-fashioned 60W light bulb, do you need more light than that to perform a specific task?  If that's the case,  you're probably looking for something with a higher light output. This used to be tricky as so many decorative fixtures were limited by the heat generated by a filament lamp (60W = 60W of heat!) and I'm sure that you've seen "60W max" labels on shades and reflectors. Fortunately, the linkage between heat and light differs in each type of light source.

A CFL equivalent lamp is likely to be 20W, so there's scope to get more than the 60W-equivalence into a "60W max" fixture, though you may find the bigger lamps not sitting comfortably within the fittings.
LEDs are becoming even more efficient, and 12W lamps are now becoming available with that level of light output, with brighter lamps promised. Physical size here is also an issue, with most manufacturers trying to limit the size of the lamp, and that's causing some stress with their promises of higher light delivery.

BUT: for now - you know how much light you can get from a conventional "60W max" fixture. Only expect marginal improvements on those figures. If you need more light, you're likely to need additional fixtures - or fixtures offering an altogether different 'light package'.

There is also an issue with the amount of light when we look at how these low-energy lamps distribute their light.

Looking at the two lamps in the photo here you can get an indication of a new situation that we've not really experienced before.

{IMG}

The CFL (top) distributes its light from the glass tubes and they emit in all directions (one of the problems these have with their light efficiency is the way that some light gets trapped in the central space between the glass tubes). This means that the CFL  operates very much like an old 60W light bulb.

The LED lamp (bottom) is effectively a half-sphere, and as light travels in straight lines, this lamp only emits in a hemi-sphere (more or less). It means that it CAN work very well in some fixtures but perform appallingly badly in others.
For example, in the two installation photos here (taken in my office) you can see how the CFL (no shade fitted) distributes its light upwards+outwards+downwards, while the LED lights predominantly outwards and downwards.

{IMG}

The CFL (left) lights in all directions, including onto the ceiling, whereas the LED lamp (right) has almost no light on the ceiling.
A small difference, perhaps, but telling if you want to fit a table fixture with a low energy lamp - that portion of light 'out of the back' of the light source becomes very important.

{IMG}

As this image shows, we usually want downwards light from table fixtures, onto the table surface. The upwards light to the ceiling is incidental.


Coming back to the lighting in my office again, I have two sources of illumination:

The ceiling pendant in the corner is located directly above an old (but wonderfully elegant) Bieffe drawing board. Its used these days as a general work table - useful for layouts, cutting  board and electrician's desk for wiring up lighting samples.

{IMG}

There is no shade on the pendant because I haven't got round to it, but also because I am gaining maximum efficiency from the naked lamp (24W DIALL 'Lotus' lamp from B&Q). The image above demonstrates how that entire corner of the room is illuminated by the lamp, and I'm using the light-coloured walls as reflectors to shift light even further around the room.
In this instance, its about light in all directions, clean and shadow-free.

My work-desk however, is a different case entirely.
Using computers has revolutionised the way that we light our work spaces. Whereas in pre-screen days we needed sufficient light to illuminate the horizontal desk surface, to support our writing and reading, today most of our attention is given to a self-illuminated screen and for as long as we can see the keys on the keyboard (something that catches me out on a regular basis) then we're not looking for the same levels of illumination.
As the work 'envelope' gains light from a window - further supported by the Lotus lamp in the pendant - lighting above my desk only needs to illuminate the local landscape of the worktop itself.

This has given me the opportunity to go with a 'style statement'. I bought the spotlights that are mounted above the notice board sometime in the early 80s, from a company called Inside-Out Lighting; long since defunct.
Already 'retro' by some thirty years in 1980, they now represent (to me at least) a Lost World of lighting design.

{IMG}

They were originally designed to house the uber-popular PAR38 spotlamp, the display lamps beloved of high street fashion shops until around 1985. Once the low voltage lamp overtook these old monsters, fixtures like the Inside-Out spot-fitting became redundant - and its taken another revolution, the LED lamp, to give the fixture a new, relevant, life.
(stay with me on this one, because it IS relevant - this is not just a walk down memory lane)
I don't need a spotlight above my desk, but I do want a directional lamp - upwards light into the cowl of the fitting is irrelevant to me, and this is where the hemi-spherical distribution of the LED bulb comes in. These iconic spot-fixtures are now fitted with state-of-the-art light sources that were unthinkable when the fixtures were designed/made.
This is important.

2. Where is the Light?

We seem to have segued into the issue of where the light is being delivered.

There are times when its not MORE light we need, its just that the light we have is in the wrong place. As you can see from above, I am dropping light directly onto my office desk - lighting, on the way down, the semi-ornamental notice-board over the desk.

There is a simple relationship that we need to appreciate when performing any visual task (a posh term that simply means doing things that need us our eyes to be able to do them): we should have a direct and uninterrupted view of the task, and the available light should fall uninterrupted between us and the task - so no shadows on the task area.

Here's another picture from the Coach House.
You're looking at the corner of our living space that is diagonally opposite our TV set; a few things to consider, then.

{IMG}

Annabel needs sufficient light to be able to see her sewing and knitting work (plus the crosswords and sudoku puzzles), but that light needs to be generated discreetly so that there is no reflected light in the TV screen. This is a floor-standing (Task Floor Light) from Original BTC Ltd ( an original title, you have to admit). The metal shade conceals the same type of LED lamp that I use in the Inside-Out spot fixtures in my office. It delivers a higher percentage of its light than the equivalent CFL lamp, making a more comfortable visual environment to perform the more demanding tasks - like threading needles.

You can see another example of putting light relevant to the task in the distance in the photograph. The yellow drum shade hangs over Annabel's work-table.
It distributes its light predominantly downwards, via the drum-skin diffuser that you can see. We reduced the wasted upwards light (wasted in this case given that we have a high, pitched, barn roof) by fitting a secondary diffuser on the top of the drum shade that reflects a good proportion of the upwards light back downwards.

And, of course, the light washing around inside the drum shade brings to life the creative Shibori-style patterns produced by Annabel for her Townhill Studio business.

{IMG}

A final example from the Coach House comes from our galley-style kitchen. When we first came here, the only general light came from the uplighting that you can see here - a fluorescent tube mounted in a channel behind a wooden 'pelmet'. Hopelessly inadequate, tending to downright dangerous.

{IMG}

But not wishing to alter the architectural nature of the original lighting pattern (such as it was) I decided to enhance the kitchen lighting by adding a single - tres elegant - fixture that sits beneath the uplight, but providing direct illumination to the kitchen space beneath.
It is nothing more than a very posh fluorescent batten, though the tubular diffuser is made from a very efficient polycarbonate that delivers a wonderfully soft light - and the fluorescent lamp is top of the range, as you might expect.

I'm always on the look-out for serendipitous moments in my designs, and we got one here.
You can see that the fluorescent fixture is mounted above a narrow window. This window establishes the 'natural' light flow into the space; it tells us where the outside world is. What I hadn't expected to the degree that we've experienced, is the extent to which the additional fluorescent lighting has an 'outdoors feel' about it - as if its mimicking the effect of the daylight coming through the window.

3. What does the Light say?

And finally, a few words about what the light is telling us. There are many variations in the WHITEness of  light sources, and its important to have an understanding of what they do.

But first, let's look at the other aspect of colour, that of Colour Rendering. Until the burgeoning growth of the LED, colour rendering had ceased to be an issue. Colour rendering was good, even in those lamps coming from supermarket shelves. LEDs changed that situation. There is currently no standard in LED lamp production and not all companies follow an acceptable protocol for colour rendition. I suspect that some companies don't know what they're doing, or are preferring to ignore the issue.
This is not good enough.

Back to Colour Temperature - sometimes called colour appearance.
The colour temperature of a lamp determines whether we see a 'cold' or 'warm' environment. Looking back to the old 60W light bulb, the technical description of the filament lamp was that its colour temperature is 2700K (measured in degrees Kelvin). Those small reflector lamps that fit into downlights in the ceiling are slightly 'cooler', at 3000K. Its unusual to want anything 'cooler' than that in a domestic setting, unless its in a utility room or workshop / art studio.
Its one of the weirderies of the physics that the higher the temperature, the cooler the appearance of the lamp. There is a reason for this.

The area that gives us most concern in this regard is in LED lamp development. LEDs are most efficient at the cooler end of the WHITE spectrum, and some manufacturers prefer to promote efficiency figures while sacrificing colour quality. This is foolish behaviour that just upsets their customers.

Low energy light bulbs are NOT filament lamps; they create their light in a completely different way, and as a consequence, their light is markedly different. There is not so much YELLOW as you see with a filament lamp - the warmth of tone is usually PINKER, and this can be a bit disconcerting.

The higher orders of the LED industry are seeking to reduce this colour shift - it is often considered to be detrimental to the acceptance of the LED as a domestic light course - and I am sure that the situation will improve across the industry over the next couple of years.
But for now - our lives are changing colour . . . just by a little bit.

 

RIBA CPD in 2015

Here are the links to my event calendars


Events

Address

John Bullock Lighting Design
The Coach House
2 East Mill Court
East Mill Lane
Sherborne
Dorset
DT9 3DP
England

Website designed by Alacrify