Shedding some light on lighting...


Understanding the benefits of using energy efficient lighting is easy; save energy, save money, save the environment. However, understanding the technical side of lighting is a little more complex.

To help do this, today's blog will try to help you understand what is meant by lux, lumens and candela - all terms used to explain lighting.

From the '70's onwards, lighting was measured in terms of Candela; which is defined as the power emitted by a light source in a given direction. The formula for working out candela is quite complex, however, the general rule of thumb is that one common household candle produces the intensity of roughly one candela.

A lumen, on the other hand, is a measure of the power of light perceived by the human eye. It is often referred to as the total amount of visible light in a defined beam or angle. Over the last few years, particularly with the development of LED lighting, there has been a shift towards measuring in terms of lux.

Lux is different to lumens as it takes into account the area that is being covered by the light source. For example, if a bulb emits 1,000 lumens over a one metre area, it will light up with 1,000 lux. However, if this same light is spread over a larger of area of 10 metres, this produces a dimmer light of only 100 lux. The formula is 1 lux is equal to 1 lumen per m2.

For a quick comparison guide, see the table below.








Now you understand how it works, click to visit our energy saving light bulbs and start making your savings!