Seven Screens is the new light art project implemented along the headquarters of OSRAM GmbH in Munich to provide artists with a platform for media art. Designed as a landmark, the seven masts with LED screens are a new urban highlight in the Bavarian capital.Munich, Mittlerer Ring. The streets are deserted, seem desolate. Then, all of a sudden, a tidal wave covers the rows of houses, the facades of the buildings reflected in the water. Two people are seen floating in the water, trying to find their balance in near-weightless movements that strike one as odd. What seems like a surreal vision of the future is actually part of the "2027" video installation of the artistic duo of Haubitz+Zoche, displayed from late April until the end of June and then again from August to the end of October within the scope of the light-related art project, Seven Screens.
Seven Screens refers to seven almost six metre high light masts with over-sized projection screens fashioned on the occasion of the 100th anniversary of the OSRAM brand. They will serve to display pieces of art that will change every six months and will be produced by selected light and media artists. OSRAM Light Consulting GmbH, the company responsible for the mast concept and the projections, provided both sides of the masts with modern 6 x 1 metre LED screens capable of projecting static or moving images. For the conception of the Seven Screens, the designers at OSRAM Light Consulting referred to the physics of light. Light is a form of electromagnetic radiation that the human eye is engineered to see. The wavelengths of the visible radiation range from 380nm (blue colour) to 780nm (red colour). Each colour is related not only to a particular wavelength but also to the temperature of what is known as 2/4 Planck's radiator, which, similar to a piece of red-hot iron, glows in different colours at various temperatures. Using this colour model (CIE standard colour table), white light sources are found on the Planck curve. The seven light masts are arranged along the OSRAM headquarters based on this curve. This configuration creates space and turns the masts into a metropolitan element that defines a new quality of urban developments on the otherwise unused green space in front of the building. The masts interact with passing cars and simultaneously act as a link between different typologies: the OSRAM headquarters in the south, flats in the north, and leisure and sports facilities on the Isar in the west.
The masts consist of a steel frame construction and are provided with contrastenhancing laminated sheet glass in one piece so as to avoid interrupting the projected image by joints. The reduced design and choice of materials for the masts is guided by the conservative language of forms of the OSRAM building, which was designed by the recently deceased architect Walter Henn within the scope of the 1962 contest project. Walter Henn, whose work as a professor at the TU Braunschweig significantly influenced the industrial and commercial architecture of his time, used the building to develop an architectural standard for a whole generation of open-plan offices. The building is one of the prime examples of the "Braunschweig school", which – as the answer to the architecture of the National Socialism – propagated the "international style" in Germany. Thanks to the OSRAM headquarters, this architectural trend has now also established itself in Munich; a few years ago, the building at Hellabrunner Strasse was carefully renovated and today is under a preservation order.
High-power LEDs for brilliant images
The aim of the light art project was to create something that would unmistakably be linked with the OSRAM name. That light as a visual symbol for the group would play a key role here was a given. The design team at OSRAM Light Consulting decided to incorporate the company's own gallery into the project and thus to create a platform for media art. In order to ensure ideal conditions for the pieces of art produced by the light artists, the steel frames of the masts were provided with the latest lighting technology from OSRAM: due to the lack of space, the LED boards installed were specifically designed and produced for this project. Each board unit is fitted with 256 OSRAM 6- 3/4 lead MultiLEDs and measures 160 x 160 millimetres. On the whole, each screen surface is made up of 216 units, with two screens per mast. This means that each of the masts weighing in at three tons contains 110,592 high-power LEDs. More than three quarters of a million LEDs have been installed for the Seven Screens.
The LEDs are based on thin-film technology and have been specially developed for optical display screens as required for the light art project and provided with a contrast-enhancing cover glass. Each LED contains one blue, one red, and one green chip which can be controlled individually to allow additive colour mixing. Due to the extreme brightness of 5,000 Candela per square metre, these light sources produce a brilliant image even in sunlight. To prevent excessive glare in less ambient light, the screens are adjusted to the natural lighting conditions via ambient light sensors. A cloudy day, twilight and nights, for example, only require six per cent of the maximum brightness to project the quick movements of the video installation onto the screens. A particular challenge proved to be the temperature management because of tightly packed electronics due to the limited installation space. The solution: the heat of each LED board generated during operation is controlled using a specially developed ventilation system and discharged to the outside.
Perfect transmission thanks to fibre optics
The LEDs of a screen are spaced ten millimetres apart and form a dot screen of 576 x 96 dots. Each of these light diodes is capable of mixing well over 16 million colours and can be controlled individually. The screens can therefore display any type of static and moving images. The LEDs are controlled from a central computer room, with customised software enabling all popular video and image formats to be played at specific times on predetermined calendar days. The works of art are transmitted to the control computer and assigned a playback time. The computer room is connected with the masts located at a distance of up to 50 metres via fibre optic cables. Their high signal transmission rate ensures that the video material is sent to the masts without delay – to ensure that the water can flow over the masts in quick, flowing movements. With the innovative technology of this light art project, OSRAM follows the 100-year brand tradition of continuously reinterpreting light.
