Seeing better with dynamic lighting

Tunable white lighting adds to comfort and convenience in an ophthalmology practice

Constantly changing lighting conditions are part of everyday life in an ophthalmologist’s office and have an influence on a person’s circadian rhythms. Both staff members and patients benefit particularly from lighting that changes according to the rhythm of light throughout the day. This is demonstrated in the refurbished offices of the eye consultants Augenspezialisten Saar in Püttlingen.


The shift between light and dark determines the daily work routine in an ophthalmologist’s practice. External examinations of the eye, reading and colour tests require bright lighting of 1000 or 500 lux according to DIN 12464-1. The surroundings need to be darkened when examining the inner eye using a slit lamp and lens. These everyday situations require varying lighting levels. Generally, this means that doctors or their assistants often need to open and close the curtains and switch lights on and off using wall switches. This was also the case in the Püttlingen clinic of Augenspezialisten Saar, before it was modernised in late 2020 and an innovative lighting concept was implemented.


The practice rooms do not have much natural light and the waiting room is the brightest area. Dynamic natural lighting resulted in an enormous improvement in conditions for conducting examinations. It also made a noticeably more comfortable atmosphere for patients during their time in the practice. Tunable white LEDs simulate the natural pattern of light over the course of the day to harness the positive effects on circadian rhythms as defined by human centric lighting (HCL).


The lighting controls operate with Casambi. It adjusts the colour temperature and illuminance continuously over the course of the day according to the actual time. A sensor in the waiting room registers real-time data and transmits them to the controls. This modern wireless technology is also easy to integrate when refurbishing an existing building. It allows you to program different lighting moods, for example for specific examinations.


The light in the offices in Püttlingen varies during the day from warm white 2700 Kelvin to cooler 5000 Kelvin and back again to 2700 Kelvin. This curve is variable and easy to adapt to fit the requirements in each case. The lighting consists of three components. Light strips on the ceiling provide diffuse light, comparable with the daylight sky. Downlights emit brilliant light directly. Swivelling spotlights in the track system in the ceiling afford improved spatial perception.


Casambi offers several interfaces, e.g. the app, a wall-mounted or wireless switch. These are easily within reach during examinations. A reed contact is integrated in the slit lamp. This contact switches the light on or off with fade time as wished. This interrupts the programmed brightness curve; the controls are then restored exactly to the current mode. This maintains the sense of continuing to experience the diurnal rhythm consciously.

The project has been awarded with an "Honorable Mention" at the LIT awards 2021.

Fotos: Sarah Pulvermüller


From practice to theory: Tobias Link appointed lecturer for Interior Works/Light at Trier University of Applied Sciences

In the 2019/2020 winter semester, Tobias Link taught fifth-semester students at the faculty of interior design at the Trier University of Applied Sciences Design Campus. Along with learning the theory, students were able to experience the medium of light first-hand during field trips and workshops.


In 1991, Tobias Link founded Lighting Design Studio Tobias Link together with Oliver Link. He has accumulated expertise from the many years he has spent working as a lighting specifier, luminaire designer and developer of control systems. As a lecturer he wanted to get across to students in a tangible way how light works and how it influences people. His message: if you know what good lighting is, then you can also put it into effect in a project for the client so that it functions successfully and is aesthetically appealing.


Tobias Link shared his profound knowledge of the subject by way of experiments and workshops. His curriculum for the short semester also included three field trips. At Broy Lichttechnik in Trier, students had an opportunity to slip into the role of the specifier and find out about contemporary lighting design and the current standards of technology. The visit to the Saarland State Theatre in Saarbrucken took in the artistic aspects, of how to use light to create mood and which illuminants to use for this. The visit to Möbel Martin in Saarbrucken provided students with greater appreciation for a large-scale project realised by Lichtplanungsbüro Tobias Link, where a biodynamic lighting concept was implemented in accordance with the Human Centric Lighting (HCL) principle. Here, the topic explored was that of lighting controls and directing light within various ceiling systems.


These intensive practical aspects constituted an entirely new approach for students and met with an extremely positive response. Students’ final papers proved that they had no difficulty in putting what they had learned into practice. The ten prospective interior designers had to design a luminaire and also draw up a lighting concept for a floor plan for a living and working space. Designing a luminaire involved developing a light attachment for the Plug & Light socket from Insta Lighting, who provided the modules. Students used the university’s own workshops to build their prototypes. At the end of the semester, they presented their work in the form of drawings, 3D models and storyboards. Students will be submitting their luminaire designs as part of the “LUXI - Der Licht-Preis” design competition run by the Licht journal in 2020.

Students’ reactions: “We’ve learned an incredible amount; that’s something we realise whenever we talk to students who are farther on in their courses. “We learned so much in the course, we’ve never explored subjects in such depth. Before this, we’d never had anything to do with Light Distribution Curves, for example.“

Tobias Link’s reaction: “I’m delighted that after just one semester they have all gained an understanding of the subject area. They are familiar with the terminology and they’re well informed about LED technology. That’s huge progress.”

Many thanks to iGuzzini and Insta Lighting for their friendly support!


The lighting for the Merzig city park focuses on the subtle interplay of light and shadow

As part of the redevelopment of the city park in Merzig, Saarland, a new lighting concept has been realised that allows the wide variety of trees and plants to be experienced even in the dark.


Merzig municipal park is used by residents and visitors to the town as a place for relaxation and recreation. Its location is central for the town centre, the civic hall and the river Saar. The park is characterised by a wide range of mature trees, some of which are decades old. In order to make this green space more attractive, the town planners commissioned a facelift of the park. The lighting concept plays a key role in this.


The underlying concept for the lighting design is to pick out individual trees and groups of trees, accentuating their form and beauty. The park overall has been planned similarly to that of a stage in a theatre. The protagonists are the trees, which radiate light from the inside, without the luminaires themselves being visible.


People are influenced by the sun and the moon that give rise to poetic images of light and shade. Just as in nature, in Merzig park the light comes from above and is projected straight down. The luminaires are mounted in the trees, as high as 30 metres up. They cast both distinct and blurred outlines of the branches and leaves onto the ground. This atmospheric impression is achieved by using three different beam angles with just a single model of luminaire.


Each tree is individual, one of many solo performers on the ‘park stage’. After consulting with the landscape gardeners, it was decided how to distribute the luminaires. Ultimately, priority was given to adjusting each individual luminaire on site, using cherry pickers to install them. The beams of light have been configured in such a way that the paths are washed with glare-free 3000 K light. A few uplights are used to pick out low-growing plants.


A multi-use pavilion was designed as an entranceway to the park. Downlights have been integrated unobtrusively into the pavilion ceiling and provide uniform wall washing. New lighting masts (mounting height of 4.50 m) now illuminate the approach and reveal the immediate surroundings of the civic hall. In-ground, recessed linear luminaires trace the outlines of the architecture and highlight the benches. Lighting for the natural salt spring will follow once restoration work has been completed.


As visitors enter Merzig municipal park, there is welcoming light to guide them and provide a sense of safety and tranquillity at any time of day or night. The natural balance of light and shade, brightness and dark is retained.

Photos: Tom Gundelwein


A lighting concept for the urban environment in a ‘shared space’ in Bertrange

The traffic routes and usable space in Bertrange, Luxembourg were redesigned to achieve traffic calming in line with the principles of ‘shared space’ that enable all road users to share the space on equal terms. The lighting plan plays a key role in this and is based entirely on LED technology.


The Bertrange council applied the concept of ‘shared space’ to the town centre with the aim of reducing traffic and improving safety. This approach originated in the Netherlands and is based on all road users being equally considerate of other users, without the need for traffic signs or demarcations. Using targeted lighting of the public place has made it possible to guide drivers, cyclists, pedestrians and children alike and to improve the quality of the leisure space.


The master plan concentrated on five areas: traffic routes, footpaths in the park, parking spaces, accent lighting in changing colours for individual buildings and atmospheric illumination of historical buildings and green spaces. It is like the direction of a theatre production, with a backdrop of vertical surfaces in the form of buildings and trees and the shared space as the stage.


Lighting masts with asymmetric lens systems project light onto the traffic routes. Their mounting height (5 m) is lower than that of the other street lights in the district. Posts that emit rays of light stand along the side of the church; they light up the footpaths. Pale-coloured paving and the uniform illumination level of 3000 K go to create a Mediterranean atmosphere.


On the paths through the park, non-glare illuminated cube seats are arranged along the paths through the park, they also serve to break up the green spaces at the events pavilion, which, along with the town hall, is among the new buildings. Another key feature is the climbing frame that, once illuminated in colour at night, resembles a light sculpture. Lighting schemes in alternating colours, which change with the seasons, were designed for the town hall. Mid-range LEDs have been incorporated on the inside of the windows and provide homogeneous light in the rooms. High-power LEDs with a narrow beam project light onto the concrete columns outside. The operator of the pavilion for hosting events continues with this play of coloured light. Illumination of the historical church and Schloss Schauwenburg castle is more distinctive with sweeping warm-white light, which accentuates surfaces and detailing.


Lighting of the parking spaces is slightly dimmer, with narrow beam illuminated bollards and low lighting masts (MH 3.5). Only a few models of luminaire are used, making maintenance easier and resulting in a harmonious overall impression. This is how to design an urban open space that conveys a sense of safety and invites people to linger.

Photos: Tom Gundelwein
Aerial View: Marc André Stiebel


Dynamic lighting design as a communications concept at G Data

G Data Software from Bochum has designed antivirus software for over 30 years. The lighting in the reception area, canteen and events space is based on an intelligent network structure, reflecting the firm’s key business.


G Data’s head offices are on an former industrial site; the central entrance into the main building houses the reception with a counter. The firm’s core business is the development of IT security systems; this was the starting point for the design approach in order to come up with a functional and representative lighting plan.


At the time the contract to create a lighting concept was awarded, the ceilings were entirely clad with sound proofing. They were replaced by a new layer, which appears as an open grid linked by individual cells. An abstract World Wide Web depicted by using complex general lighting and energising lighting schemes.


The white network structure in the reception area describes a striking architecture constructed with custom-designed moulded parts made from plasterboard . They supply two fundamental lighting components: indirect and direct light. The rounded honeycomb structures serve as cornice lighting; they provide the indirect light with integral rows of RGB LEDs and the colour temperature can be adjusted. A 4-cm-wide light channel runs along the linear axes, through which direct light with two beam angles is generated. Highly efficient tunable white LED lights are used here, the colour temperature of which can be regulated. Star-like lines of light also radiate across the floor towards the counter.


The three-dimensional ceiling sculpture leads from the reception area to the canteen in a modified form as stepped wood facets. The structure appears to float light as a feather and creates a homelike atmosphere; slender pendant lights are used for selective accent lighting and deliberately break up the branching structure.


The user-friendly controls provide for four different lighting schemes: a natural light setting, which is sent information via an external sensor and transmits it into the inside; two party settings with changing colours, which use saturated colours in warm or cooler shades, as well as task lighting for cleaning and maintenance work. The lighting system operates biodynamically, by adjusting to the natural light and supporting people’s natural day/night rhythm in line with aspects of human-centric lighting (HCL).


Cubic exterior lights are used in the events hall. They emphasise the sober industrial architecture, can be dimmed separately and the colour temperature can be varied. General lighting for training courses and lectures as well as changing coloured lighting moods breathe fresh life into the room as needed.

Photos: Tom Gundelwein


The Löhr Centre in Koblenz creates atmosphere with tunable white

The Löhr Centre in Koblenz is one of the largest inner-city shopping centres in the Rhineland Palatinate. It was renovated by ECE as it had been in operation for over 30 years. A fundamental element of the refurbishment was a comprehensive lighting and colour concept.


An initial draft of the lighting design for the Löhr Centre, which opened in 1984, was created in 2014, when partial modernisation of the 32,000 sqm sales area was planned. In March 2016, ECE decided to renovate all three floors, where around 130 shops are located today. The lighting plan had to be completely revised by the time of reopening in spring 2017 and finished while the shopping centre was open for business.


As part of the relaunch, a new interior design was chosen that divided the mall into three sections: “The Lobby” was depicted in energising blue, green and yellow, “The Boutique” in stimulating red, blue purple and turquoise, “The Collection”, with its floor-to-ceiling bookcase, as a highlight in warm red, purple and yellow.


The lighting concept picks up from these colour schemes in the form of decorative, geometrical light panels, which create an impressive ceiling design. Coloured film serves as filters, where the colour effect varies depending on the time of day. Distribution of the high-performance LEDs in a dense 10 cm grid ensures that the luminous effect is extremely homogeneous. In the daytime, the general lighting has high luminous intensity with a cool colour temperature of 4000 K, the decorative ceiling lights create a strong contrast with warm light up to 2200 K. In a night-time setting with subtle general light, the light panels produce a strong contrast with 4000 K.


The lighting concept is based on energy-efficient LED technology with tunable white, four lighting moods are created by using luminous intensity and colour temperature. These moods are produced using day/night lights with a special Fresnel lens system, which distributes direct and indirect light to the optimum. Perfectly shielded lights are built into a streamlined LED strip system that is just 4 cm wide, so that accented light appears like patches of sunlight, which are only perceived unconsciously. An exterior sensor captures the natural light values; the controls operate according to an automatic programme.


Additional mood spots provide light in the seating and display areas. Special pendant lights with metal grid shades, up to 4 m in diameter and 3 m in height, fill the mall visually and accentuate the welcoming character of the Löhr Centre.

Photos: Tom Gundelwein


A biodynamic lighting concept for Möbel Martin in Kaiserslautern

Light has a positive impact on us. Above all, when it feels authentic. This was the maxim for the lighting project in the Möbel Martin group’s store when it underwent refurbishment in 2015. The brief was to redesign the 30,000 m2 showroom area during the course of modernisation. The challenging project included the development of a bespoke LED light and a modular lighting system, which sets a new technical standard with its dynamic controls for natural light.

A harmonious balance

There were strict conditions governing how the lighting project was to be implemented. The deadline was tight, the system had to ensure that investment and maintenance costs were kept low, that upkeep was simple and the existing HIT downlights were replaced with energy efficient ones. Previously,16 different types of lights had been in use and did not spread light evenly. The lighting concept was therefore aimed at giving the whole property a visually homogeneous frame.

Individual in grand style

Open floor spaces and large areas, display booths, the specialist ranges with exhibition pods and the kitchen department constitute the main areas of the furniture store. The focus is clearly on the products on show, the linear design of the lighting is less conspicuous visually. The bespoke light now replaces a large number of different models. It has two reflectors (with a narrow or wide beam) and there are curved versions so it can adapt to different ceiling situations. It is practical and can be positioned to suit. Reflectors with a narrow light beam project onto areas such as cooking islands or banners. In the case of shelf or pod fronts, the light spreads downwards evenly without the shelves needing separate lighting. Reflectors with wide beams ensure a balanced level of light and pleasant atmosphere. The high colour rendering of the illuminants guarantees that impressions of finishes and colours are realistic.

Taking the sun as model

Sunlight governs our circadian rhythms and important processes in our bodies. The high-performance LEDs work with “tunable white”: depending on actual conditions on the outside of the building, they provide a spectrum similar to natural light from 3000 to 5000 K, which energises or relaxes. This also results in a high potential for savings. Today’s LED technology makes it possible to achieve solutions of this kind in the area of “human-centric lighting” (HCL). The new modular system is 55% more energy efficient to operate and offers maximum comfort, both for customers and staff. The bespoke light is now available as a standard light. “instalight PROSALE 1021” is the obvious solution for widespread use in shops.

Photos: Tom Gundelwein


A lighting concept for the new offices of ADAC Mittelrhein in Koblenz.

The design is planned for two floors of offices and the ADAC shop. The brief was to continue the organic design language from the interior and create lighting that was suitable for computer workstations and offered staff maximum comfort and yet was energy-efficient.

Good at cornering

The offices in the ADAC building were designed for one to five people and separated from the corridors by glazing, The corridors stand apart clearly with their curved design: areas accented with colours are intended as places for communication. White light makes the sunny yellow meeting points look bright and cheerful.

Easy navigation

General lighting in the corridors is provided by downlights with a neutral white colour temperature of 4000 K; their lenses resemble the Xenon headlights of cars. In order to link typical ADAC subjects, such as driving or map reading, with the architecture, the ceiling lights are connected by lines. This results in an overall impression that reminds one of street maps and traffic lights. The lines follow the architecture and lead along the corridors like waymarks.

Forward march for technology

There was limited room for scope in the ceiling design as a result of the overhead heating and cooling in the offices. Special pendant lights based on LEDs create a separate level, they provide functional light and comply with requirements with regard to heat dissipation and power consumption. The pendant lights project direct and indirect light, one or two are installed in each room. Prisms ensure that, with a length of up to 210 cm, light is spread evenly. Lights are turned on manually. They are switched off automatically using a movement detector. Staff can also choose the individual level of illuminance as they wish and are not restricted to the standard figure of 500 lux. In addition, a sensor regulates the light adjustment for natural light.

Lane changing in colour

Each pendant light is fitted with an RGB unit that is regulated by central controls and its own bus system so that the building exterior is illuminated after dark. Blue light shines indirectly onto the white surfaces of the ceiling, with the result that ADAC's offices and the leased floor appear in a uniform midnight blue. In addition, the shop, which by day is illuminated with a pendant track system on the dynamic coloured ceiling, is integrated in this installation.

Fotos: Tom Gundelwein

Project participants:

Förster + Förster Architekten, Bad Kreuznach | Bals + Wirth Innenarchitekten, Wiesbaden | Münch und Münch GmbH & Co.KG, München


Light in context with traditional wine growing and contemporary architecture: Weingut Franz Keller in Oberbergen

Design of the lighting for this major project only got underway after the initial building phase had already been completed, when most of the installation points for lights and wiring were already in place. Wine growing and wine tasting, restaurant, events, sales and office spaces are spread over three floors.

Harmonious hillside vineyard

With its distinctive concrete and glass architecture, the new building for the Franz Keller vineyards blends in harmoniously with the terraced vineyards on the Kaiserstuhl. In this case, the lighting concept had to meet several conditions: adapt to the existing electrical connections, satisfy all lighting specifications and do justice to the high standards of design dictated by the structure of the building.

A view of fine wines

The room where the grapes are delivered is also available for events. In order to achieve lighting that is both atmospheric and also meets DIN standards for task lighting, we developed a bespoke LED light that operates both with two beam angles and two colour temperatures. The droplet shape of the glasses continue the theme of wine with their shape. In addition, cornice lighting using RGB colour mixing projects different mood lighting onto the ceiling. An additional cornice scatters amber-coloured light over the restaurant, providing a warm and intimate atmosphere.

Discovering wines

The lighting concept supports the open-plan layout and merges separate complexes such as the room for grape deliveries or the salesroom using visual effects. A glass strip in the floor that can be walked over gives a glimpse of the cellar below with the barriques and wood casks. All the wiring and data transmission lines run through a purpose-developed cable duct for the lighting. The housing for the lights is also a bespoke solution: it is made of special, acid-resistant stainless steel.

From the grape harvest to the light harvest

Bespoke lighting and light objects obviously relate to the wine-growing traditions of the family business and the landscape of the region. A chandelier with a canopy made of 50-year-old vines is suspended over the restaurant bar; in the tasting room a filigree pendant light decorates the oval table and reflects its shape and size. Lastly, an illuminated relief of the landscape illustrates the different layers of earth in the vineyard as a cross-section. The design was nominated for the German Lighting Design prize in 2014.

Photos: Tom Gundelwein

PRIMA KLIMA (climate clever)

Lighting design for the “CO2 and Co.” exhibition [“COzwo und Co”] on the subject of climate protection in the Schaumberg tower in Tholey.

The exhibition commissioned by the Saarland ministry for trade and Industry covers an area of 140 m², spread over two floors in the tower. Our brief was to design lighting that showcased the exhibits and could be switched on and off automatically.

A guided voyage of discovery

"CO2 and Co." was divided up into different subjects: climate crisis and renewable energy, traffic and transport, environmentally friendly, healthy food and ecological farming and forestry. The exhibition was aimed at all ages, from school classes through to visits by tourists. In addition to the above-mentioned educational concept, a separate tender was held for the lighting design. The climate exhibition was intended to be self-explanatory and encourage visitors to experience the exhibits interactively and through all their senses.

Four colour schemes

Dynamically changing colours are assigned to each of the above-named areas. Special light fixtures with RGB LEDs scatter the light assigned to that area into the rooms as soon as visitors enter. The lights are attached to the ceiling using magnets and need just 12 mm for installation. They contain all the required technical equipment and are wired in series, so that they can be controlled sequentially.

Gentle light

As the architecture only allows for a low ceiling height, there was limited space for installing the lights. When it came to general lighting, 2.5 W LED lights with a low installation depth of 2 cm were chosen. The illuminants result in stimulating lighting with warm white light of 3000 K, with power consumption of just 3.4 W/sqm. A savings in energy that certainly meets the standards of "CO2 and co.” in full.

Visible results

Development work on the lighting concept and media control unit resulted in several modules: the blue light in the water lounge imitates ripples, a translucent fabric serves as a room divider and surface for projection, which can be seen from two sides; a peep show makes the visible invisible to the observer – using blue-red images, which are illuminated with blue or red light. The cinema with its concave design shows films that can be watched on an iPad. The exhibition, which was opened in August 2013 and which calls on each visitor to show individual initiative, was planned to run for five years. Photos: Sebastian Caspary