The LED is more than just a »little light«. Numerous manufacturers of luminaires have adjusted their portfolio very sharply in the direction of LEDs, and conventional types of luminaire are increasingly being pushed into the background. One of the most important markets for LED lighting installations is the industrial sector. Here the competition is very keen. Huge industrial buildings with extensive production, dispatch and storage areas promise a lot of attractive business.

Human Centric Lighting, or HCL, is the English term for lighting which takes into account the non-visual effects of light. This current area of research, which focuses in particular on the influence of optical radiation on the health of humans, is exposed to two threats: on the one hand, being appropriated by very aggressive marketing from the lighting industry and, on the other hand, being hindered by critics who quickly sense a threat in any kind of progress.

In lighting design, when working independently of any manufacturer interests, one is often faced with the question of which product to use for a desired application. The technical requirements are, of course, defined in the plans but still the question remains: which manufacturer has the best product with the best price/performance ratio? On the market there are numerous similar products whose differences it is very difficult to recognize.

Within a period of just a few years the LED has become the dominant artificial light source and has taken over in nearly all fields of lighting. We have witnessed a disruptive change which has made any previous technology obsolete. How much further will this trend go? What is an LED capable of and what is it not able to do and where do we find »ecological niches« for non-semiconductor light sources?

Exactly five years ago, in August 2011, a new version of EN 2464-1 for lighting in work places was released. This new version added new criteria and procedures to the previous version. The question is, however, whether these innovations have proved their worth. After our experience with this standard how do we assess it today?

It is important in lighting design that there is no flicker and that there are no strobe effects. Visually perceptible flicker is definitely a deficiency. But even flicker at high frequencies which are beyond the visually perceptible range should not be ignored. Studies have shown that this type of flicker can have an influence on the human organism.

The efficiency of lamps has increased considerably in recent years with the use of white LEDs in the field of architectural lighting. Retailers claim that we can expect a gigantic leap forward in luminous efficacy. Such claims cannot be taken seriously. What does luminous efficacy depend on and how efficient can a white LED actually be?

Recently the term »Human Centric Lighting«, abbreviated to »HCL«, has been appearing in marketing communications of numerous luminaire manufacturers - especially in connection with LED products. It seems that there is not only »Standard Lighting Design« but also »HCL Lighting Design«. Is this really the case? What exactly is behind this catchword?

The purpose of colour rendition is to show how »right« the surface colour seems to the observer under artificial lighting. This has to do with the recognition of colours or nuances of colour for all daily activities which take place in artificial light such as shopping, working or in the home. It is not only since the success of LED s that the question of a more meaningful metric for colour rendition remains to be answered. A very promising candidate for such a metric is hidden behind the abbreviation TM-30-15.

Daylight is a precious asset of incredibly high quality. It has an invaluable influence on the well-being of all mankind. And even in the world of work which mainly takes place under artificial light, there are new strains of thought which take the relevance daylight into account. This article will give a short introduction to the fundamentals of daylight and will provide two examples of norms/regulations which dealing with artificial lighting in places of work in which reference to daylight is now included.

Daylight is synonymous with natural light which reaches the earth from the sun. It is only available during the daytime, hence its name, in the time period between sunrise and sunset. Within the field of artificial lighting there are however an increasing number of products which promise to simulate natural daylight realistically. What is behind this?

There is an app for everything. With this promise smartphone manufacturers want to make everyday life easier for us. There are even numerous apps available for the lighting and architectural sector. Luxmeter apps. But can these replace a professional measuring device?