Urbanscreen at Gasometer Oberhausen

URBANSCREEN, an internationally-renowned group of artists, creates breath-taking projections on architectural structures. The group uses its "Lumentecture" art process, in which every element of the projection correlates with the individual features of a structure. The art is built using projectors from Epson's Z-10000 Series.

At the installation, visitors carefully feel their way through a narrow door into a huge cylinder at Gasometer Oberhausen. The surroundings are suddenly transformed: on the formerly dark 100-metre high wall, white ribbons of light runup and down, swirling around one another until they finish in cascades of dots. The construction of the building is transformed through the use of light and is a perfect example of URBANSCREEN's work.

For this sculpture , 21 projectors from Epson's Z-10000 Series project light onto a large area of around 20,000 m² – one of the largest interior projections in the world. Because of the large size of the wall, it's not only the timing and size of the projections that have to be in sync; the sound and echo (which is unavoidable due to the cylindrical shape of the interior) must also be measured. The building also presented its own challenges, as Thorston Bauer, the group's Creative Director explains:. "The walls of the Gasometer are painted tar black and therefore have a low reflection factor. This means we don't get much light back. Also, the roof and the entrances let a large amount of outside light in and we had to do lots of covering and hanging up."

The 21 projectors are split into seven banks of three machines that are accurately aligned with one another. Each projector bank covers an angle of approximately 45° at a height of around 100 metres. With a projection size such as this, even small errors in the projections would disrupt the desired visual effect. One example of these errors is the tolerances of the individual optics or 3LCD chips, which is unavoidable. To correct these errors, URBANSCREEN uses a method called warping. This is where each projection from each projector is split into a total of 64 separate fields; they can be geometrically and colourimetrically calibrated independently of one another. All systemic image defects from the projectors are rectified in this way. It results in an accurate projection, even over huge areas.

To obtain a better understanding of the challenges the technology faces with architectural structures such as this, precise models and drafts are required. A 3D model of the architecture is created using a laser measuring system normally used in geodesy. It measures the distances from a reference point to the surrounding walls and generates a 3D model of the space using the millions of data points it receives. This model then serves as the basis for creating the projection. If a bar sticks out of the wall in a certain place, this will be present in the 3D model and can be illuminated in a different way . "To create a better simulation of certain aspects of this project, we have also constructed a 1:25 scale model of the Gasometer and set it up in our studio's cellar," explains Bauer. "We use this model to get our first impressions of the planned projection."

"320° Licht" was planned to run for nine months, six days a week, eight hours a day, from April 2014 to December 2014. The projectors would be running in Winter and summer conditions. On location, if the outside temperature drops below freezing in winter, it will get very cold in the unheated interior. If it reaches over 30°C in the height of summer, the cylinder won't be much cooler than that. There could also be high or low humidity, and the air could become polluted with dust. None of these conditions are ideal for high-performance projectors on continuous operation. If a bulb should fail, the Z-Series operates a dual bulb system, meaning URBANSCREEN has a backup ready to immediately take over.

" Projectors can never be too bright, too small or too light when used in this type of project. Although the current machines are more advanced and powerful than those we used in our first projects in 2005, there is always room for more," adds Bauer. "The lumen per euro value is very important to us. We used to purchase a 10,000 lumen projector for around EUR20,000 For an exhibition like this, we have 21 projectors in continuous operation and also some as backup, so cost plays a big part." Bauer explains that the projection technology is also important. He says: "1-DLP projectors are not suitable for this kind of work. Moving light elements with high contrast can give you a rainbow effect. The picture is often not as steady with DLP projectors as it is with those using 3LCD technology (included in Epson's Z-1000 Series). Epson's devices are also freely rotatable within the space, making them much easier to position."

URBANSCREEN

Large-scale projections on city surfaces; this is the group's core pursuit. The group focuses on using the architecture and taking the nature of a building, its inhabitants and passers-by into consideration. The company was founded in 2005 when the city of Bremen applied to be the European Capital of Culture. One of the projects used in the city's application was the former multimedia wall in Steintor in Viertel, Bremen, which investigated the effect of media, among other things, on public space. Based on this approach, the idea to create projections that fitted exactly onto the existing architecture came to be. The eight members combine various disciplines, including architecture, music and set design, as well as digital art forms such as CGI and motion graphics.

URBANSCREEN has become internationally renowned through projects involving the Sydney Opera House and Rice University in Houston, Texas.

Contact: URBANSCREEN, Am Deich 86, 28199, Bremen

Tel: +49 421 460 74 40, www.urbanscreen.de

Intermediate Engineering GmbH

"Intermediate Engineering GmbH - Ingenieurbüro für Medientechnik" is responsible for parts of the technical implementation. On virtually every one of URBANSCREEN's projects, they are in the background to ensure the technology works perfectly.

Contact: Intermediate Engineering GmbH, Rödingsmarkt 14, 20459 Hamburg

Tel: +49 40 361 225 86, www.im-en.com