QUALITY FEATURES
OF GOOD LED LIGHT SOURCES

Quality at a glance

Bargain hunters take note – because when it comes to the light source market, the saying ‘you get what you pay for’ certainly applies. And this doesn’t just affect your wallet, but sometimes your health and personal well-being too! Because not everything on the LED market that looks attractive and shines brightly is actually good and safe. It has now been repeatedly demonstrated and proven just how important light quality is for our daily well-being, our mood and our health. That’s why there are a few quality features of good LED light sources to look out for – then nothing can go wrong. 

IDENTIFYING HIGH-QUALITY LED LIGHT SOURCES

What is part of everyday expertise for lighting designers and electricians is often difficult for consumers to recognise and understand. The market is flooded with LED light sources, and the range on offer is almost limitless in its variety. But as a non-professional, how do I recognise the quality features of an LED light source? A few tips and basic concepts can help you pick out the most important ones. 

1. LIFESPAN

Manufacturers usually specify the lifespan of an LED in hours. High-quality LED light sources can be identified by a lifespan of 20,000 hours or more. However, it is important to distinguish between filament LEDs and traditional diodes using SMD technology, which generally have a longer lifespan. The number of switch-on cycles also plays a significant role. An LED light source at home is, of course, switched on and off more frequently than in a commercial setting, e.g. retail spaces, medical practices, corridors, halls, etc. Every switching operation affects the lifespan, albeit not to the same extent as with conventional incandescent bulbs or halogen bulbs with a filament. Reputable manufacturers therefore also specify the number of switch-on cycles, and in some cases even the decline in luminous flux – that is, the reduction in light output once the service life has elapsed. This is because the stated service life does not mean that the LED simply stops working, but rather the point at which it still emits the minimum amount of light required by law. The loss of luminous efficacy is very slight at first. However, if an LED appears noticeably dimmer after the specified number of hours, then it is indeed time for a replacement. This is because, as a rule, this decline becomes even more pronounced as the light source continues to operate. 

2. QUALITY FEATURE: COLOR RENDERING

The Color Rendering Index, or CRI for short, indicates how well colors are rendered under the light of a particular LED light source. The ideal value is 100, which represents sunlight. So the closer the value is to 100, the better the quality. This value also declines slightly over time. 

In some applications, the CRI is certainly a value that can be disregarded, whilst in others it is all the more important. After all, we want to leave the hairdresser’s with the right hair color, don’t we?

3. THE FLICKER INDEX

Flicker-free performance or the flicker index – a factor that has only recently come to be taken seriously and is now becoming increasingly important. Many cheap LED light sources (mainly dimmable ones!) flicker, often imperceptibly to the naked eye, but still noticeably. There is a very simple way to find out if the light source you’ve bought flickers – the camera method; how it works is explained here! The so-called SVM value, which measures flicker, is now also being included in EU regulations for LED light sources. For high-quality LEDs, this value should be below 0.4. Another value relating to flicker is the Pst, which indicates the flicker intensity over 10 minutes. This should be below 1. 

4. TEMPERATURE MANAGEMENT

LEDs like it cool! The lifespan of an LED depends largely on its operating and ambient temperatures. Low-quality LED light sources lack effective heat management, or rather, manufacturers do not prioritise it, as this entails additional materials and costs. However, if heat builds up within the LED due to inadequate heat sinks or heat spreaders, premature failure is practically inevitable. The operating temperature must be stated on LED light sources; simply look for this, as it indicates the temperature range within which the LED should be operated to ensure its full lifespan is achieved. The wider this range, the higher the quality of the LED.

5. QUALITY CHARACTERISTIC: COLOR OF LIGHT / COLOR TEMPERATURE

The color temperature should be chosen to suit each specific location. Find out exactly what these are here! 

 As a general rule:

• <3000 Kelvin: warm white, cosy, relaxing, soothing 
• 3300 – 5000 Kelvin: neutral white, bright, friendly, inviting 
• >5300 Kelvin: daylight white, stimulating, cool, daylight-like 

Due to the technology used to produce the colors of light in filament light sources via a fluorescent coating, there can be significant differences in color temperature with cheap light sources. Inferior materials, varying density and thickness of the conversion layer within the filament, or a layer that is too thin usually result in poor color consistency! 

6. THE ELECTRONICS

Last but not least: an LED ALWAYS requires a driver to convert the alternating current from the mains supply into direct current.

This electronics unit is the most expensive component in the LED light source; consequently, there is plenty of scope for cutting corners here and saving a lot of money by using inferior materials. Incorrectly selected parts and poor workmanship are the main reasons for the failure of the electronics and, consequently, of the LED light source. 

Unfortunately, the end consumer usually has very little influence or insight into what is used in this area, as the electronics are not visible in the base of most standard LED light sources. 

WHAT ALWAYS APPLIES: 

High-quality LED light sources may seem expensive at first glance, but they pay for themselves very quickly. Efficient, energy-saving and with a long lifespan, they are simply the best the lighting market currently has to offer. An investment in the future, both in the commercial and private sectors! And let’s not forget the environment: good LED light sources contain no toxins such as mercury, are recyclable, and their long lifespan results in an excellent ecological footprint. When, as with SEGULA, care is taken to ensure resource-efficient and clean production, you’re not only doing your wallet a favour, but also your health AND the environment!