eye There is more to LED
Lighting than meets the eye
LED (Light Emitting Diodes)
Lighting is rapidly evolving into what we now accept will be the future of all lighting.
Chips with Everything!
LED lighting uses many types of LED chips from a huge range of manufacturers. CREE, Nichia, Philips, Osram, Samsung, Bridgelux, Edison, Epistar and many others.

Each brand has its own range of products and types of chip. SMD (Surface Mounted Device) and COB (Chips on Board) are the most commonly used. The performance or grade of chip is usually defined by how many lumens per watt it can achieve, but there is another, often overlooked factor in how good the chip is, CRI.

CRI (Colour Rendering Index) or Ra is a measure of how accurately a light source can reproduce colour. The scale used is 0-100, loo being the highest amount achievable, as in natural daylight.

LED chips with a high CRI offer a more complete mix of the light spectrum. As you can see from the chart below natural daylight offers a fairly even mix of the primary colours of the spectrum, whereas standard fluorescent tubes are deficient in some colours, which ones depends on whether they are classed as Warm White or Cool White.

pioneers like Dr John Ott in the 1970's, discovered that fluorescent lighting is very deficient in some parts of the lighting spectrum. Also that there are Electromagnetic Emissions (Known today as 'Dirty Electrcity') emanating from the fluorescent ballasts and electrodes in a range that can affect human health. Ott discovered that these inherent factors in the design of fluorescent lighting can cause a myriad of health problems, both physical and psychological.

Ott then took his research into schools in and found that children and staff who worked under a more complete spectrum of light with shielding on the electrodes, were
far less stressed, had higher levels of concentration, fewer sick days and actually achieved better academic results than the classes who were still working under standard spectrum-deficient, fluorescent lighting.

More interestingly, by using time-lapse photography in the classroom, Ott was able to demonstrate that those normally disruptive and less attentive pupils became calmer and more focused on the lessons.



LED technology

Is advancing at a furious pace, prices are falling and a plethora of products are now making their way onto the UK market. As many buyers will have already found to their cost, there can be a considerable variation in quality and performance of LED products.

Although externally many LED products might look very much the same, internally they can be very different. The majority of manufacturers in the China (where most LED products are made) use the same suppliers for the outer shells or casings. It is a little like computer cases, if you took away the manufacturer's badges, they would all look much the same on the outside, but what's inside, can be vastly different!

As an example, here are two 50 watt LED floodlights. The one on the left has a high quality 45mil Bridgelux chip and quality power supply from Taiwan. The one on the right has a 38 mil Chinese Chip with Chinese power supply. Can you see any difference?

They may look identical but the higher quality version will last a lot longer, give much more light and the power supply will give many years of good service, so 'Buyer Beware'.


Standard fluorescent tubes produce a CRI of around 65-70.

A standard Cool White LED tube will offer around 70-75 CRI however it is possible to obtain LED tubes and other LED products with a much higher CRI of around 80-90.
These products use higher graded chips and special phosphors to achieve the superior quality of light. You pay a little more at the outset, but the benefits can be enormous, as you will see in the following.

"Good Lighting Can Improve Educational Performance"

That may seem like a bold statement, but there has been a tremendous amount of research over the years into the quality of lighting in schools and the results do confirm it.

Good lighting is not just about quantity of light, but also the quality of that light
Research into the effect that fluorescent lighting has on plant and animal life, by


This research has been repeated by other groups since and yielded similar results. Fortunately, with the arrival of LED lighting, the issue
with high energy ballasts is no longer a problem and the ability to produce a more natural spectrum
of light with LED is now achievable.

All life has evolved under natural daylight and there will never be a substitute for that, but in many buildings, it is simply not possible to have natural daylight in every area where it is needed.

Choosing good lighting, with a balanced light spectrum is probably one of the more important investments that you can make for your pupils and staff.

By providing the best possible working environment, you are giving everyone the best opportunity to achieve their full potential.

LED4light is a specialist LED lighting business who work closely with manufacturers to produce superior LED lighting products.

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