Starting out as a lighting engineer in a television studio, I learnt the basics of light density, intensity and quality to get the best possible image from a studio camera. It’s no different when taking our holiday snaps. Just by trial and error we work out where to stand for the best light and how much light is going to be too much or too little to gain a good picture.
Of course television studio cameras and even the common hand held automatic cameras have made huge advances in technology in more recent years adding greater sensitivity to light, massive pixel counts to gain greater detailed images and wider colour rendering to improve on more realistic colour correctness.
Office and domestic lighting have also had some big changes in the last ten years in terms of technology towards efficiency, lighting effects and quality of light, but the lighting manufacturers need lighting designers, architects and lighting savvy technicians to bring the excellence of available lighting to homes and offices, but why?
Placing the right type of lighting in the right location for specific tasks needs a rational approach to the selection of lighting with a higher colour correctness whether for work or relaxation unlike utility spaces where a lower colour correctness can be fine.
Providing enough ambient light, fit for purpose without over power consumption and purchasing too many lights is a real skill. If you provide a classic 1 metre square grid of downlights, the chances are that you may have over purchased the lighting and also signed the customer up to higher lighting running costs than is necessary, not to mention the ceiling aesthetics showing a blanket of multiple holes!
So a lighting designer will consider the following four elements:
Density – this is the amount of light in a space e.g. We need a high density of light around a book for reading the book but where we are just sitting watching TV or just relaxing a much lower density of light is needed, the density of lighting is measured in Lux.
Intensity – this relates to the quantity of light emitted from a lamp measured in lumens, this is most obvious on a dark night with a torch, you get a defined beam of light and the intensity of light is measured at specific distances from the light source to allow the designer to work out how much light will wash and reflect from a beam of light.
Quality – This refers to the accuracy of the light emitted by the lamp in relation to the light produced by the sun. As a simple example, we know that a tomato is red and not orange and we can confirm this by taking a tomato outside in daylight to check the colour, however under poor quality lighting, this same tomato might look closer to orange than red. This principle goes hand in hand with the type and specification of the lamps (bulbs) and the light fittings that the lamps fit in, but also the finishes of the walls, floors and ceilings and their colours also play a key part in the whole quality of light in a room and that rooms ability to show near to true colour or perhaps enhance room colours to amplify colour and create dramatic effect
Quality of light from a lamp can be measured directly as a colour rendering index(CRI), sunlight being the benchmark at 100 CRI.
Colour temperature – This refers to the colour of light emitted from the lamp and is measured in Kelvin (K). So a candle light would be around 1700K, a warm white light is between 2500K and 3000K, as this temperature climbs in value to say 4000K the light colour changes to a neutral pure white light. Going higher at around 5500k is near sunlight in colour. Increasing the colour temperature on to 7000K starts to introduce a blue colour to the light, this might be called cool white in colour.
So following these basic elements above you can see that there is a great deal more to lighting than what you might have considered at first and it is the combination of all these elements including the reflective surfaces of a space and natural light too that must be considered if you are to control the light carefully in a building to provide the right type of lighting for the right location and activity in the space during the day and through the night too.
So looking at lighting spaces means that lamps are selected on the basis of the four elements above and positioning them for ambient, task lighting and effect lighting. Using wide angle beam lamps and narrow angle beam lamps in light fittings to provide flood and spot lighting respectively. There are also many different types of light fittings that enhance the light with accurately engineered reflectors, some squeeze the light through slots or magnifying lenses, some offer the most beautiful dispersing of soft light with colour and tint. You can create spaces of theatre with delicate touches of light accenting the building space as well as vivid colours and movement. Enhance daylight, enhance night time and simulate daylight.
Dimming of lighting – Dimming or just simply lighting control from a programmable controller can also help enormously to achieve the contrast of light and dark in a space and also offer differing accent of lighting to cope with daylight use and night time use of the same spaces. This is aside from the more obvious benefits like reduced power consumption through smarter control, mood lighting and remote control features from whole building control, feedback of lamp life and change of lighting for change of use in multipurpose spaces.
Lighting automation. Linked with dimming controllers, lighting automation can save money, provide extra safety and change lighting based on active real time sensing within a building to maximise efficiency.
I hope these few points demonstrate the need to look a little deeper into the overall quality of a lighting design. I’ve seen many projects where an architect’s preliminary building designs utilises a generic lighting layout to be properly designed later but the generic design gets costed as is and hence makes it all the way to the installation. This is such a pity since with a little input from a lighting expert, so much more could have been delivered for the client at little, if any, additional cost.
So what goes into a tailored lighting design?
A lighting expert will use their experience to ask and understand from the client what the spaces will be used for and how the spaces will flow from entry to exits. What aesthetics will the client be looking for. Ascertain the ideal level of lighting in each space – some people prefer quite dark and low lighting and some prefer higher levels of lighting. What features if any will be fitted? From water features to glass staircases and glamorous balustrades. From chandeliers to crystal feature lights. From a period style to a modern or contemporary one. Whatever colours and surfaces are chosen, every part of the building space inside and out should be considered before the wiring infrastructure is designed, planned and fitted.
As a final point, it must be remembered that whilst the lighting may well be installed towards the end of the project, we need to think earlier and earlier about it in the project’s planning. Advances in technology and the care of a well thought through design can bring so many more options and possibilities to our fingertips. However only early consideration of the possibilities will make the most of the points raised in this blog. But if we do so, a better quality of lighting tailored to our building’s needs and the people who use them will create happier spaces in which to live and work!