A life of colour in light
Time was, no one had to worry about colour when it came to choosing light sources (lamps/bulbs/globes).
Incandescent light was always the same Kelvin (temperature) a warm 2700K, and every lamp produced the perfect spectrum of colour - CRI100.
Then came the CFL (compact fluorescent "twisty" lamps) upgrade. We banned the incandescent and everyone had to buy fluro lamps for their home lights. Across the country, homes were suddenly cool bluish white and colours seemed muted. This is because CFL comes in (generally) 2 different colour temperatures (3000K and 4000K) being warm and cool white and has a CRI80 rating - meaning (in simple terms) that it produces 80% of the full rainbow of colour in the spectrum that is white light (known as Colour Rendering). Most people are used to this light in offices and commercial properties, but in a home, it had quite an impact. Add to these factors the fact that many lower priced CFL lamps didn't have the expected life they were supposed to provide, and many had long warm up times and every home owner has been waiting for the ultimate solution ever since.
Welcome LED. Sure, it's low energy consumption (most of the time) but making the right selection for your home lighting is now even more complex, requiring an understanding of the technicalities of light that has never been required before - and is very rarely taught.
LED comes in every colour temperature from warm - 2800K through to bright blue cold 6500K. So, making sure you choose the right temperature is suddenly far more important. Most homes aim for 3000K, some people prefer the cooler 4000K. When choosing an LED, it's vital you get this step right or you will end up with an ambience you don't want in your home.
When it comes to the colour spectrum of LED however, this is where it gets murky. Having never really had the choice before, most people have been unaware that choosing the right CRI rating for their LEDs has a huge impact on how their home looks and feels. Most average quality LED product now come in at a CRI80 rating (this was not always the case). Higher quality products are CRI90 or CRI95. The higher the number, the more of the rainbow in the light, ergo, the more of your colours that you'll see accurately.
However, to make matters even more complex, the way CRI is measured can sway the rating to show a high number, without actually providing the full spectrum.
So - How do you make sure you're getting high quality light from your LED fittings?
It all comes down to asking the right questions, using reputable suppliers - and testing the light for yourself. This can be tricky in a lighting store where there are so many lights on a once, they all blend together to give the appearance of great colour rendition.
You need to be clear about the colour temperature (K) that you want. Select 3000K or 4000K for warm or cool. A supplier should be able to provide this with a minimum of variation within the temperature - known as McAdam steps or SDCM - this should be no more than 3 steps.
Second, and most important - you need to decide how good your colour rendering needs to be. Are you happy with office fluro CRI80 or do you want your face/artworks/clothes/furniture etc to be shown in their true colours. If you care about the colour, then you need to ensure you buy minimum CRI90 in LED.
With this information under your belt, hopefully the next time you find yourself looking at LED lights, you'll feel a little more confident that you have the right questions to ask to get what you want.
To engage Mint Lighting Design to provide all this knowledge and more on your next home lighting project, please contact us today for a consultation.